OpenFPGA/openfpga/src/fabric/build_mux_modules.cpp

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2020-02-12 20:45:14 -06:00
/***********************************************
* This file includes functions to generate
* Verilog submodules for multiplexers.
* including both fundamental submodules
* such as a branch in a multiplexer
* and the full multiplexer
**********************************************/
#include <string>
#include <algorithm>
/* Headers from vtrutil library */
#include "vtr_log.h"
#include "vtr_assert.h"
#include "vtr_time.h"
#include "mux_graph.h"
#include "module_manager.h"
#include "mux_utils.h"
#include "circuit_library_utils.h"
#include "decoder_library_utils.h"
#include "module_manager_utils.h"
#include "build_module_graph_utils.h"
#include "openfpga_reserved_words.h"
#include "openfpga_naming.h"
#include "build_mux_modules.h"
/* begin namespace openfpga */
namespace openfpga {
/*********************************************************************
* Generate structural Verilog codes (consist of transmission-gates or
* pass-transistor) modeling an branch circuit
* for a multiplexer with the given size
*
* +----------+
* input[0] --->| tgate[0] |-+
* +----------+ |
* |
* +----------+ |
* input[1] --->| tgate[1] |-+--->output[0]
* +----------+ |
* |
* ... ... |
* |
* +----------+ |
* input[i] --->| tgate[i] |-+
* +----------+
*********************************************************************/
static
void build_cmos_mux_branch_body(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const CircuitModelId& tgate_model,
const ModuleId& mux_module,
const ModulePortId& module_input_port,
const ModulePortId& module_output_port,
const ModulePortId& module_mem_port,
const ModulePortId& module_mem_inv_port,
const MuxGraph& mux_graph) {
/* Get the module id of tgate in Module manager */
ModuleId tgate_module_id = module_manager.find_module(circuit_lib.model_name(tgate_model));
VTR_ASSERT(ModuleId::INVALID() != tgate_module_id);
/* Get model ports of tgate */
std::vector<CircuitPortId> tgate_input_ports = circuit_lib.model_ports_by_type(tgate_model, CIRCUIT_MODEL_PORT_INPUT, true);
std::vector<CircuitPortId> tgate_output_ports = circuit_lib.model_ports_by_type(tgate_model, CIRCUIT_MODEL_PORT_OUTPUT, true);
VTR_ASSERT(3 == tgate_input_ports.size());
VTR_ASSERT(1 == tgate_output_ports.size());
/* Find the module ports of tgate module */
/* Input port is the data path input of the tgate, whose size must be 1 ! */
ModulePortId tgate_module_input = module_manager.find_module_port(tgate_module_id, circuit_lib.port_prefix(tgate_input_ports[0]));
VTR_ASSERT(true == module_manager.valid_module_port_id(tgate_module_id, tgate_module_input));
BasicPort tgate_module_input_port = module_manager.module_port(tgate_module_id, tgate_module_input);
VTR_ASSERT(1 == tgate_module_input_port.get_width());
/* Mem port is the memory of the tgate, whose size must be 1 ! */
ModulePortId tgate_module_mem = module_manager.find_module_port(tgate_module_id, circuit_lib.port_prefix(tgate_input_ports[1]));
VTR_ASSERT(true == module_manager.valid_module_port_id(tgate_module_id, tgate_module_mem));
BasicPort tgate_module_mem_port = module_manager.module_port(tgate_module_id, tgate_module_mem);
VTR_ASSERT(1 == tgate_module_mem_port.get_width());
/* Mem inv port is the inverted memory of the tgate, whose size must be 1 ! */
ModulePortId tgate_module_mem_inv = module_manager.find_module_port(tgate_module_id, circuit_lib.port_prefix(tgate_input_ports[2]));
VTR_ASSERT(true == module_manager.valid_module_port_id(tgate_module_id, tgate_module_mem_inv));
BasicPort tgate_module_mem_inv_port = module_manager.module_port(tgate_module_id, tgate_module_mem_inv);
VTR_ASSERT(1 == tgate_module_mem_inv_port.get_width());
/* Output port is the data path output of the tgate, whose size must be 1 ! */
ModulePortId tgate_module_output = module_manager.find_module_port(tgate_module_id, circuit_lib.port_prefix(tgate_output_ports[0]));
VTR_ASSERT(true == module_manager.valid_module_port_id(tgate_module_id, tgate_module_output));
BasicPort tgate_module_output_port = module_manager.module_port(tgate_module_id, tgate_module_output);
VTR_ASSERT(1 == tgate_module_output_port.get_width());
/* Ensure that input port size does match mux inputs */
BasicPort input_port = module_manager.module_port(mux_module, module_input_port);
VTR_ASSERT(input_port.get_width() == mux_graph.num_inputs());
/* Add module nets for each mux inputs */
std::vector<ModuleNetId> mux_input_nets;
for (const size_t& pin : input_port.pins()) {
ModuleNetId input_net = module_manager.create_module_net(mux_module);
mux_input_nets.push_back(input_net);
/* Configure the source for each net */
module_manager.add_module_net_source(mux_module, input_net, mux_module, 0, module_input_port, pin);
}
/* Ensure that output port size does match mux outputs */
BasicPort output_port = module_manager.module_port(mux_module, module_output_port);
VTR_ASSERT(output_port.get_width() == mux_graph.num_outputs());
/* Add module nets for each mux outputs */
std::vector<ModuleNetId> mux_output_nets;
for (const size_t& pin : output_port.pins()) {
ModuleNetId output_net = module_manager.create_module_net(mux_module);
mux_output_nets.push_back(output_net);
/* Configure the sink for each net */
module_manager.add_module_net_sink(mux_module, output_net, mux_module, 0, module_output_port, pin);
}
/* Ensure that mem port size does match mux outputs */
BasicPort mem_port = module_manager.module_port(mux_module, module_mem_port);
VTR_ASSERT(mem_port.get_width() == mux_graph.num_memory_bits());
/* Add module nets for each mem inputs */
std::vector<ModuleNetId> mux_mem_nets;
for (const size_t& pin : mem_port.pins()) {
ModuleNetId mem_net = module_manager.create_module_net(mux_module);
mux_mem_nets.push_back(mem_net);
/* Configure the source for each net */
module_manager.add_module_net_source(mux_module, mem_net, mux_module, 0, module_mem_port, pin);
}
/* Ensure that mem_inv port size does match mux outputs */
BasicPort mem_inv_port = module_manager.module_port(mux_module, module_mem_inv_port);
VTR_ASSERT(mem_inv_port.get_width() == mux_graph.num_memory_bits());
/* Add module nets for each mem inverted inputs */
std::vector<ModuleNetId> mux_mem_inv_nets;
for (const size_t& pin : mem_inv_port.pins()) {
ModuleNetId mem_net = module_manager.create_module_net(mux_module);
mux_mem_inv_nets.push_back(mem_net);
/* Configure the source for each net */
module_manager.add_module_net_source(mux_module, mem_net, mux_module, 0, module_mem_inv_port, pin);
}
/* Build a module following the connections in mux_graph */
/* Iterate over the inputs */
for (const auto& mux_input : mux_graph.inputs()) {
/* Iterate over the outputs */
for (const auto& mux_output : mux_graph.outputs()) {
/* Add the a tgate to bridge the mux input and output */
size_t tgate_instance = module_manager.num_instance(mux_module, tgate_module_id);
module_manager.add_child_module(mux_module, tgate_module_id);
/* Add module nets to connect the mux input and tgate input */
module_manager.add_module_net_sink(mux_module, mux_input_nets[size_t(mux_graph.input_id(mux_input))], tgate_module_id, tgate_instance, tgate_module_input, tgate_module_input_port.get_lsb());
/* if there is a connection between the input and output, a tgate will be outputted */
std::vector<MuxEdgeId> edges = mux_graph.find_edges(mux_input, mux_output);
/* There should be only one edge or no edge*/
VTR_ASSERT((1 == edges.size()) || (0 == edges.size()));
/* No need to output tgates if there are no edges between two nodes */
if (0 == edges.size()) {
continue;
}
/* Add module nets to connect the mux output and tgate output */
module_manager.add_module_net_source(mux_module, mux_output_nets[size_t(mux_graph.output_id(mux_output))], tgate_module_id, tgate_instance, tgate_module_output, tgate_module_output_port.get_lsb());
MuxMemId mux_mem = mux_graph.find_edge_mem(edges[0]);
/* Add module nets to connect the mem input and tgate mem input */
if (false == mux_graph.is_edge_use_inv_mem(edges[0])) {
/* wire mem to mem of module, and wire mem_inv to mem_inv of module */
module_manager.add_module_net_sink(mux_module, mux_mem_nets[size_t(mux_mem)], tgate_module_id, tgate_instance, tgate_module_mem, tgate_module_mem_port.get_lsb());
module_manager.add_module_net_sink(mux_module, mux_mem_inv_nets[size_t(mux_mem)], tgate_module_id, tgate_instance, tgate_module_mem_inv, tgate_module_mem_inv_port.get_lsb());
} else {
/* wire mem_inv to mem of module, wire mem to mem_inv of module */
module_manager.add_module_net_sink(mux_module, mux_mem_inv_nets[size_t(mux_mem)], tgate_module_id, tgate_instance, tgate_module_mem, tgate_module_mem_port.get_lsb());
module_manager.add_module_net_sink(mux_module, mux_mem_nets[size_t(mux_mem)], tgate_module_id, tgate_instance, tgate_module_mem_inv, tgate_module_mem_inv_port.get_lsb());
}
}
}
}
/*********************************************************************
* Generate Verilog codes modeling an branch circuit
* for a CMOS multiplexer with the given size
* Support structural and behavioral Verilog codes
*********************************************************************/
static
void build_cmos_mux_branch_module(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const CircuitModelId& mux_model,
const std::string& module_name,
const MuxGraph& mux_graph) {
/* Get the tgate model */
CircuitModelId tgate_model = circuit_lib.pass_gate_logic_model(mux_model);
/* Skip output if the tgate model is a MUX2, it is handled by essential-gate generator */
if (CIRCUIT_MODEL_GATE == circuit_lib.model_type(tgate_model)) {
VTR_ASSERT(CIRCUIT_MODEL_GATE_MUX2 == circuit_lib.gate_type(tgate_model));
return;
}
std::vector<CircuitPortId> tgate_global_ports = circuit_lib.model_global_ports_by_type(tgate_model, CIRCUIT_MODEL_PORT_INPUT, true, true);
/* Generate the Verilog netlist according to the mux_graph */
/* Find out the number of inputs */
size_t num_inputs = mux_graph.num_inputs();
/* Find out the number of outputs */
size_t num_outputs = mux_graph.num_outputs();
/* Find out the number of memory bits */
size_t num_mems = mux_graph.num_memory_bits();
/* Check codes to ensure the port of Verilog netlists will match */
/* MUX graph must have only 1 output */
VTR_ASSERT(1 == num_outputs);
/* MUX graph must have only 1 level*/
VTR_ASSERT(1 == mux_graph.num_levels());
/* Create a Verilog Module based on the circuit model, and add to module manager */
ModuleId mux_module = module_manager.add_module(module_name);
VTR_ASSERT(true == module_manager.valid_module_id(mux_module));
/* Add module ports */
/* Add each input port */
BasicPort input_port("in", num_inputs);
ModulePortId module_input_port = module_manager.add_port(mux_module, input_port, ModuleManager::MODULE_INPUT_PORT);
/* Add each output port */
BasicPort output_port("out", num_outputs);
ModulePortId module_output_port = module_manager.add_port(mux_module, output_port, ModuleManager::MODULE_OUTPUT_PORT);
/* Add each memory port */
BasicPort mem_port("mem", num_mems);
ModulePortId module_mem_port = module_manager.add_port(mux_module, mem_port, ModuleManager::MODULE_INPUT_PORT);
BasicPort mem_inv_port("mem_inv", num_mems);
ModulePortId module_mem_inv_port = module_manager.add_port(mux_module, mem_inv_port, ModuleManager::MODULE_INPUT_PORT);
/* By default we give a structural description,
* Writers can freely write the module in their styles
* For instance, Verilog writer can ignore the internal structure and write in behavioral codes
*/
build_cmos_mux_branch_body(module_manager, circuit_lib, tgate_model, mux_module, module_input_port, module_output_port, module_mem_port, module_mem_inv_port, mux_graph);
/* Add global ports to the mux module:
* This is a much easier job after adding sub modules (instances),
* we just need to find all the global ports from the child modules and build a list of it
*/
add_module_global_ports_from_child_modules(module_manager, mux_module);
}
/*********************************************************************
* Generate Verilog codes modeling an branch circuit
* for a RRAM-based multiplexer with the given size
* Support structural and behavioral Verilog codes
*********************************************************************/
static
void build_rram_mux_branch_module(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const CircuitModelId& mux_model,
const std::string& module_name,
const MuxGraph& mux_graph) {
/* Get the input ports from the mux */
std::vector<CircuitPortId> mux_input_ports = circuit_lib.model_ports_by_type(mux_model, CIRCUIT_MODEL_PORT_INPUT, true);
/* Get the output ports from the mux */
std::vector<CircuitPortId> mux_output_ports = circuit_lib.model_ports_by_type(mux_model, CIRCUIT_MODEL_PORT_OUTPUT, true);
/* Get the BL and WL ports from the mux */
std::vector<CircuitPortId> mux_blb_ports = circuit_lib.model_ports_by_type(mux_model, CIRCUIT_MODEL_PORT_BLB, true);
std::vector<CircuitPortId> mux_wl_ports = circuit_lib.model_ports_by_type(mux_model, CIRCUIT_MODEL_PORT_WL, true);
/* Generate the Verilog netlist according to the mux_graph */
/* Find out the number of inputs */
size_t num_inputs = mux_graph.num_inputs();
/* Find out the number of outputs */
size_t num_outputs = mux_graph.num_outputs();
/* Find out the number of memory bits */
size_t num_mems = mux_graph.num_memory_bits();
/* Check codes to ensure the port of Verilog netlists will match */
/* MUX graph must have only 1 output */
VTR_ASSERT(1 == num_outputs);
/* MUX graph must have only 1 level*/
VTR_ASSERT(1 == mux_graph.num_levels());
/* MUX graph must have only 1 input and 1 BLB and 1 WL port */
VTR_ASSERT(1 == mux_input_ports.size());
VTR_ASSERT(1 == mux_output_ports.size());
VTR_ASSERT(1 == mux_blb_ports.size());
VTR_ASSERT(1 == mux_wl_ports.size());
/* Create a Verilog Module based on the circuit model, and add to module manager */
ModuleId mux_module = module_manager.add_module(module_name);
VTR_ASSERT(ModuleId::INVALID() != mux_module);
/* Add module ports */
/* Add each global programming enable/disable ports */
std::vector<CircuitPortId> prog_enable_ports = circuit_lib.model_global_ports_by_type(mux_model, CIRCUIT_MODEL_PORT_INPUT, true, true);
for (const auto& port : prog_enable_ports) {
/* Configure each global port */
BasicPort global_port(circuit_lib.port_prefix(port), circuit_lib.port_size(port));
module_manager.add_port(mux_module, global_port, ModuleManager::MODULE_GLOBAL_PORT);
}
/* Add each input port */
BasicPort input_port(circuit_lib.port_prefix(mux_input_ports[0]), num_inputs);
module_manager.add_port(mux_module, input_port, ModuleManager::MODULE_INPUT_PORT);
/* Add each output port */
BasicPort output_port(circuit_lib.port_prefix(mux_output_ports[0]), num_outputs);
module_manager.add_port(mux_module, output_port, ModuleManager::MODULE_OUTPUT_PORT);
/* Add RRAM programming ports,
* RRAM MUXes require one more pair of BLB and WL
* to configure the memories. See schematic for details
*/
BasicPort blb_port(circuit_lib.port_prefix(mux_blb_ports[0]), num_mems + 1);
module_manager.add_port(mux_module, blb_port, ModuleManager::MODULE_INPUT_PORT);
BasicPort wl_port(circuit_lib.port_prefix(mux_wl_ports[0]), num_mems + 1);
module_manager.add_port(mux_module, wl_port, ModuleManager::MODULE_INPUT_PORT);
/* Note: we do not generate the internal structure of the ReRAM-based MUX
* circuit as a module graph!
* This is mainly due to that the internal structure could be different
* in Verilog or SPICE netlists
* Leave the writers to customize this
*/
}
/***********************************************
* Generate Verilog codes modeling an branch circuit
* for a multiplexer with the given size
**********************************************/
static
void build_mux_branch_module(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const CircuitModelId& mux_model,
const size_t& mux_size,
const MuxGraph& mux_graph) {
std::string module_name = generate_mux_branch_subckt_name(circuit_lib, mux_model, mux_size, mux_graph.num_inputs(), MUX_BASIS_MODULE_POSTFIX);
/* Multiplexers built with different technology is in different organization */
switch (circuit_lib.design_tech_type(mux_model)) {
case CIRCUIT_MODEL_DESIGN_CMOS:
build_cmos_mux_branch_module(module_manager, circuit_lib, mux_model, module_name, mux_graph);
break;
case CIRCUIT_MODEL_DESIGN_RRAM:
build_rram_mux_branch_module(module_manager, circuit_lib, mux_model, module_name, mux_graph);
break;
default:
VTR_LOGF_ERROR(__FILE__, __LINE__, "Invalid design technology of multiplexer '%s'\n",
2020-02-12 20:45:14 -06:00
circuit_lib.model_name(mux_model).c_str());
exit(1);
}
}
/********************************************************************
* Generate the standard-cell-based internal logic (multiplexing structure)
* for a multiplexer or LUT in Verilog codes
* This function will :
* 1. build a multiplexing structure by instanciating standard cells MUX2
* 2. add intermediate buffers between multiplexing stages if specified.
*******************************************************************/
static
void build_cmos_mux_module_mux2_multiplexing_structure(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const ModuleId& mux_module,
const CircuitModelId& mux_model,
const CircuitModelId& std_cell_model,
const vtr::vector<MuxInputId, ModuleNetId>& mux_module_input_nets,
const vtr::vector<MuxOutputId, ModuleNetId>& mux_module_output_nets,
const vtr::vector<MuxMemId, ModuleNetId>& mux_module_mem_nets,
const MuxGraph& mux_graph) {
/* Get the regular (non-mode-select) sram ports from the mux */
std::vector<CircuitPortId> mux_regular_sram_ports = find_circuit_regular_sram_ports(circuit_lib, mux_model);
VTR_ASSERT(1 == mux_regular_sram_ports.size());
/* Find the input ports and output ports of the standard cell */
std::vector<CircuitPortId> std_cell_input_ports = circuit_lib.model_ports_by_type(std_cell_model, CIRCUIT_MODEL_PORT_INPUT, true);
std::vector<CircuitPortId> std_cell_output_ports = circuit_lib.model_ports_by_type(std_cell_model, CIRCUIT_MODEL_PORT_OUTPUT, true);
/* Quick check the requirements on port map */
VTR_ASSERT(3 == std_cell_input_ports.size());
VTR_ASSERT(1 == std_cell_output_ports.size());
/* Find module information of the standard cell MUX2 */
std::string std_cell_module_name = circuit_lib.model_name(std_cell_model);
/* Get the moduleId for the submodule */
ModuleId std_cell_module_id = module_manager.find_module(std_cell_module_name);
/* We must have one */
VTR_ASSERT(ModuleId::INVALID() != std_cell_module_id);
/* Find the module ports of the standard cell MUX2 module */
std::vector<ModulePortId> std_cell_module_inputs;
std::vector<BasicPort> std_cell_module_input_ports;
/* Input 0 port is the first data path input of the tgate, whose size must be 1 ! */
for (size_t port_id = 0; port_id < 2; ++port_id) {
std_cell_module_inputs.push_back(module_manager.find_module_port(std_cell_module_id, circuit_lib.port_prefix(std_cell_input_ports[port_id])));
VTR_ASSERT(true == module_manager.valid_module_port_id(std_cell_module_id, std_cell_module_inputs[port_id]));
std_cell_module_input_ports.push_back(module_manager.module_port(std_cell_module_id, std_cell_module_inputs[port_id]));
VTR_ASSERT(1 == std_cell_module_input_ports[port_id].get_width());
}
/* Mem port is the memory of the standard cell MUX2, whose size must be 1 ! */
ModulePortId std_cell_module_mem = module_manager.find_module_port(std_cell_module_id, circuit_lib.port_prefix(std_cell_input_ports[2]));
VTR_ASSERT(true == module_manager.valid_module_port_id(std_cell_module_id, std_cell_module_mem));
BasicPort std_cell_module_mem_port = module_manager.module_port(std_cell_module_id, std_cell_module_mem);
VTR_ASSERT(1 == std_cell_module_mem_port.get_width());
/* Output port is the data path output of the standard cell MUX2, whose size must be 1 ! */
ModulePortId std_cell_module_output = module_manager.find_module_port(std_cell_module_id, circuit_lib.port_prefix(std_cell_output_ports[0]));
VTR_ASSERT(true == module_manager.valid_module_port_id(std_cell_module_id, std_cell_module_output));
BasicPort std_cell_module_output_port = module_manager.module_port(std_cell_module_id, std_cell_module_output);
VTR_ASSERT(1 == std_cell_module_output_port.get_width());
/* Cache Net ids for each level of the multiplexer */
std::vector<std::vector<ModuleNetId>> module_nets_by_level;
module_nets_by_level.resize(mux_graph.num_node_levels());
for (size_t level = 0; level < mux_graph.num_node_levels(); ++level) {
/* Print the internal wires located at this level */
module_nets_by_level[level].resize(mux_graph.num_nodes_at_level(level));
}
/* Build the location map of intermediate buffers */
std::vector<bool> inter_buffer_location_map = build_mux_intermediate_buffer_location_map(circuit_lib, mux_model, mux_graph.num_node_levels());
/* Add all the branch modules and intermediate buffers */
for (const auto& node : mux_graph.non_input_nodes()) {
/* Get the size of branch circuit
* Instanciate an branch circuit by the size (fan-in) of the node
*/
size_t branch_size = mux_graph.node_in_edges(node).size();
/* To match the standard cell MUX2: We should have only 2 input_nodes */
VTR_ASSERT(2 == branch_size);
/* Find the instance id */
size_t std_cell_instance_id = module_manager.num_instance(mux_module, std_cell_module_id);
/* Add the module to mux_module */
module_manager.add_child_module(mux_module, std_cell_module_id);
/* Get the node level and index in the current level */
size_t output_node_level = mux_graph.node_level(node);
size_t output_node_index_at_level = mux_graph.node_index_at_level(node);
/* Set a name for the instance */
std::string std_cell_instance_name = generate_mux_branch_instance_name(output_node_level, output_node_index_at_level, false);
module_manager.set_child_instance_name(mux_module, std_cell_module_id, std_cell_instance_id, std_cell_instance_name);
/* Add module nets to wire to next stage modules */
ModuleNetId branch_net;
if (true == mux_graph.is_node_output(node)) {
/* This is an output node, we should use existing output nets */
MuxOutputId output_id = mux_graph.output_id(node);
branch_net = mux_module_output_nets[output_id];
} else {
VTR_ASSERT(false == mux_graph.is_node_output(node));
branch_net = module_manager.create_module_net(mux_module);
}
module_manager.add_module_net_source(mux_module, branch_net, std_cell_module_id, std_cell_instance_id, std_cell_module_output, std_cell_module_output_port.get_lsb());
/* Record the module net id in the cache */
module_nets_by_level[output_node_level][output_node_index_at_level] = branch_net;
/* Wire the branch module memory ports to the nets of MUX memory ports */
/* Get the mems in the branch circuits */
std::vector<MuxMemId> mems;
for (const auto& edge : mux_graph.node_in_edges(node)) {
/* Get the mem control the edge */
MuxMemId mem = mux_graph.find_edge_mem(edge);
/* Add the mem if it is not in the list */
if (mems.end() == std::find(mems.begin(), mems.end(), mem)) {
mems.push_back(mem);
}
}
/* Connect mem to mem net one by one
* Note that standard cell MUX2 only needs mem but NOT mem_inv
*/
for (const MuxMemId& mem : mems) {
module_manager.add_module_net_sink(mux_module, mux_module_mem_nets[mem], std_cell_module_id, std_cell_instance_id, std_cell_module_mem, std_cell_module_mem_port.get_lsb());
}
/* Wire the branch module inputs to the nets in previous stage */
/* Get the nodes which drive the root_node */
std::vector<MuxNodeId> input_nodes;
for (const auto& edge : mux_graph.node_in_edges(node)) {
/* Get the nodes drive the edge */
for (const auto& src_node : mux_graph.edge_src_nodes(edge)) {
input_nodes.push_back(src_node);
}
}
/* Number of inputs should match the branch_input_size!!! */
VTR_ASSERT(input_nodes.size() == branch_size);
/* To match the standard cell MUX2: We should have only 2 input_nodes */
VTR_ASSERT(2 == input_nodes.size());
/* build the link between input_node[0] and std_cell_input_port[0]
* build the link between input_node[1] and std_cell_input_port[1]
*/
for (size_t node_id = 0; node_id < input_nodes.size(); ++node_id) {
/* Find the port info of each input node */
size_t input_node_level = mux_graph.node_level(input_nodes[node_id]);
size_t input_node_index_at_level = mux_graph.node_index_at_level(input_nodes[node_id]);
/* For inputs of mux, the net id is reserved */
if (true == mux_graph.is_node_input(input_nodes[node_id])) {
/* Get node input id */
MuxInputId input_id = mux_graph.input_id(input_nodes[node_id]);
module_manager.add_module_net_sink(mux_module, mux_module_input_nets[input_id], std_cell_module_id, std_cell_instance_id, std_cell_module_inputs[node_id], std_cell_module_input_ports[node_id].get_lsb());
} else {
VTR_ASSERT (false == mux_graph.is_node_input(input_nodes[node_id]));
/* Find the input port of standard cell */
module_manager.add_module_net_sink(mux_module, module_nets_by_level[input_node_level][input_node_index_at_level], std_cell_module_id, std_cell_instance_id, std_cell_module_inputs[node_id], std_cell_module_input_ports[node_id].get_lsb());
}
}
/* Identify if an intermediate buffer is needed */
if (false == inter_buffer_location_map[output_node_level]) {
continue;
}
/* Add an intermediate buffer to mux_module if needed */
if (true == mux_graph.is_node_output(node)) {
/* Output node does not need buffer addition here, it is handled outside this function */
continue;
}
/* Now we need to add intermediate buffers by instanciating the modules */
CircuitModelId buffer_model = circuit_lib.lut_intermediate_buffer_model(mux_model);
/* We must have a valid model id */
VTR_ASSERT(CircuitModelId::INVALID() != buffer_model);
/* Create a module net which sources from buffer output */
ModuleNetId buffer_net = add_inverter_buffer_child_module_and_nets(module_manager, mux_module, circuit_lib, buffer_model, branch_net);
/* Record the module net id in the cache */
module_nets_by_level[output_node_level][output_node_index_at_level] = buffer_net;
}
}
/********************************************************************
* Generate the pass-transistor/transmission-gate -based internal logic
* (multiplexing structure) for a multiplexer or LUT in Verilog codes
* This function will :
* 1. build a multiplexing structure by instanciating the branch circuits
* generated before
* 2. add intermediate buffers between multiplexing stages if specified.
*******************************************************************/
static
void build_cmos_mux_module_tgate_multiplexing_structure(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const ModuleId& mux_module,
const CircuitModelId& circuit_model,
const vtr::vector<MuxInputId, ModuleNetId>& mux_module_input_nets,
const vtr::vector<MuxOutputId, ModuleNetId>& mux_module_output_nets,
const vtr::vector<MuxMemId, ModuleNetId>& mux_module_mem_nets,
const vtr::vector<MuxMemId, ModuleNetId>& mux_module_mem_inv_nets,
const MuxGraph& mux_graph) {
/* Find the actual mux size */
size_t mux_size = find_mux_num_datapath_inputs(circuit_lib, circuit_model, mux_graph.num_inputs());
/* Get the regular (non-mode-select) sram ports from the mux */
std::vector<CircuitPortId> mux_regular_sram_ports = find_circuit_regular_sram_ports(circuit_lib, circuit_model);
VTR_ASSERT(1 == mux_regular_sram_ports.size());
/* Cache Net ids for each level of the multiplexer */
std::vector<std::vector<ModuleNetId>> module_nets_by_level;
module_nets_by_level.resize(mux_graph.num_node_levels());
for (size_t level = 0; level < mux_graph.num_node_levels(); ++level) {
/* Print the internal wires located at this level */
module_nets_by_level[level].resize(mux_graph.num_nodes_at_level(level));
}
/* Build the location map of intermediate buffers */
std::vector<bool> inter_buffer_location_map = build_mux_intermediate_buffer_location_map(circuit_lib, circuit_model, mux_graph.num_node_levels());
/* Add all the branch modules and intermediate buffers */
for (const auto& node : mux_graph.non_input_nodes()) {
/* Get the size of branch circuit
* Instanciate an branch circuit by the size (fan-in) of the node
*/
size_t branch_size = mux_graph.node_in_edges(node).size();
/* Instanciate the branch module which is a tgate-based module
*/
std::string branch_module_name= generate_mux_branch_subckt_name(circuit_lib, circuit_model, mux_size, branch_size, MUX_BASIS_MODULE_POSTFIX);
/* Get the moduleId for the submodule */
ModuleId branch_module_id = module_manager.find_module(branch_module_name);
/* We must have one */
VTR_ASSERT(ModuleId::INVALID() != branch_module_id);
/* Find the instance id */
size_t branch_instance_id = module_manager.num_instance(mux_module, branch_module_id);
/* Add the module to mux_module */
module_manager.add_child_module(mux_module, branch_module_id);
/* Get the node level and index in the current level */
size_t output_node_level = mux_graph.node_level(node);
size_t output_node_index_at_level = mux_graph.node_index_at_level(node);
/* Set a name for the instance */
std::string branch_instance_name = generate_mux_branch_instance_name(output_node_level, output_node_index_at_level, false);
module_manager.set_child_instance_name(mux_module, branch_module_id, branch_instance_id, branch_instance_name);
/* Get the output port id of branch module */
ModulePortId branch_module_output_port_id = module_manager.find_module_port(branch_module_id, std::string("out"));
BasicPort branch_module_output_port = module_manager.module_port(branch_module_id, branch_module_output_port_id);
/* Add module nets to wire to next stage modules */
ModuleNetId branch_net;
if (true == mux_graph.is_node_output(node)) {
/* This is an output node, we should use existing output nets */
MuxOutputId output_id = mux_graph.output_id(node);
branch_net = mux_module_output_nets[output_id];
} else {
VTR_ASSERT(false == mux_graph.is_node_output(node));
branch_net = module_manager.create_module_net(mux_module);
}
module_manager.add_module_net_source(mux_module, branch_net, branch_module_id, branch_instance_id, branch_module_output_port_id, branch_module_output_port.get_lsb());
/* Record the module net id in the cache */
module_nets_by_level[output_node_level][output_node_index_at_level] = branch_net;
/* Wire the branch module memory ports to the nets of MUX memory ports */
/* Get the mems in the branch circuits */
std::vector<MuxMemId> mems;
for (const auto& edge : mux_graph.node_in_edges(node)) {
/* Get the mem control the edge */
MuxMemId mem = mux_graph.find_edge_mem(edge);
/* Add the mem if it is not in the list */
if (mems.end() == std::find(mems.begin(), mems.end(), mem)) {
mems.push_back(mem);
}
}
/* Get mem/mem_inv ports of branch module */
ModulePortId branch_module_mem_port_id = module_manager.find_module_port(branch_module_id, std::string("mem"));
BasicPort branch_module_mem_port = module_manager.module_port(branch_module_id, branch_module_mem_port_id);
ModulePortId branch_module_mem_inv_port_id = module_manager.find_module_port(branch_module_id, std::string("mem_inv"));
BasicPort branch_module_mem_inv_port = module_manager.module_port(branch_module_id, branch_module_mem_inv_port_id);
/* Note that we do NOT care inverted edge-to-mem connection.
* It is handled in branch module generation!!!
*/
/* Connect mem/mem_inv to mem/mem_inv net one by one */
for (size_t mem_id = 0; mem_id < mems.size(); ++mem_id) {
module_manager.add_module_net_sink(mux_module, mux_module_mem_nets[mems[mem_id]], branch_module_id, branch_instance_id, branch_module_mem_port_id, branch_module_mem_port.pins()[mem_id]);
module_manager.add_module_net_sink(mux_module, mux_module_mem_inv_nets[mems[mem_id]], branch_module_id, branch_instance_id, branch_module_mem_inv_port_id, branch_module_mem_inv_port.pins()[mem_id]);
}
/* Wire the branch module inputs to the nets in previous stage */
/* Get the input port id of branch module */
ModulePortId branch_module_input_port_id = module_manager.find_module_port(branch_module_id, std::string("in"));
BasicPort branch_module_input_port = module_manager.module_port(branch_module_id, branch_module_input_port_id);
/* Get the nodes which drive the root_node */
std::vector<MuxNodeId> input_nodes;
for (const auto& edge : mux_graph.node_in_edges(node)) {
/* Get the nodes drive the edge */
for (const auto& src_node : mux_graph.edge_src_nodes(edge)) {
input_nodes.push_back(src_node);
}
}
/* Number of inputs should match the branch_input_size!!! */
VTR_ASSERT(input_nodes.size() == branch_size);
/* build the link between input_node and branch circuit input_port[0]
*/
for (size_t node_id = 0; node_id < input_nodes.size(); ++node_id) {
/* Find the port info of each input node */
size_t input_node_level = mux_graph.node_level(input_nodes[node_id]);
size_t input_node_index_at_level = mux_graph.node_index_at_level(input_nodes[node_id]);
/* For inputs of mux, the net id is reserved */
if (true == mux_graph.is_node_input(input_nodes[node_id])) {
/* Get node input id */
MuxInputId input_id = mux_graph.input_id(input_nodes[node_id]);
module_manager.add_module_net_sink(mux_module, mux_module_input_nets[input_id], branch_module_id, branch_instance_id, branch_module_input_port_id, branch_module_input_port.pins()[node_id]);
} else {
VTR_ASSERT (false == mux_graph.is_node_input(input_nodes[node_id]));
module_manager.add_module_net_sink(mux_module, module_nets_by_level[input_node_level][input_node_index_at_level], branch_module_id, branch_instance_id, branch_module_input_port_id, branch_module_input_port.pins()[node_id]);
}
}
/* Identify if an intermediate buffer is needed */
if (false == inter_buffer_location_map[output_node_level]) {
continue;
}
/* Add an intermediate buffer to mux_module if needed */
if (true == mux_graph.is_node_output(node)) {
/* Output node does not need buffer addition here, it is handled outside this function */
continue;
}
/* Now we need to add intermediate buffers by instanciating the modules */
CircuitModelId buffer_model = circuit_lib.lut_intermediate_buffer_model(circuit_model);
/* We must have a valid model id */
VTR_ASSERT(CircuitModelId::INVALID() != buffer_model);
ModuleNetId buffer_net = add_inverter_buffer_child_module_and_nets(module_manager, mux_module, circuit_lib, buffer_model, branch_net);
/* Record the module net id in the cache */
module_nets_by_level[output_node_level][output_node_index_at_level] = buffer_net;
}
}
/*********************************************************************
* This function will add nets and input buffers (if needed)
* to a mux module
* Module net represents the connections when there are no input buffers
* mux_input_net[0]
* |
* v +------------
* mux_in[0] ----------->|
* |
* |
* |
* | Multiplexing
* mux_input_net[i] | Structure
* | |
* v |
* mux_in[0] ----------->|
* |
*
*
* Module net represents the connections when there are input buffers
* mux_input_net[0]
* |
* +-----------------+ v +------------
* mux_in[0] ----->| input_buffer[0] |-----> |
* +-----------------+ |
* |
* ... |
* | Multiplexing
* mux_input_net[i] | Structure
* | |
* +-----------------+ v |
* mux_in[0] ----->| input_buffer[0] |-----> |
* +-----------------+ |
*********************************************************************/
static
vtr::vector<MuxInputId, ModuleNetId> build_mux_module_input_buffers(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const ModuleId& mux_module,
const CircuitModelId& mux_model,
const MuxGraph& mux_graph) {
vtr::vector<MuxInputId, ModuleNetId> mux_input_nets(mux_graph.num_inputs(), ModuleNetId::INVALID());
/* Get the input ports from the mux */
std::vector<CircuitPortId> mux_input_ports = circuit_lib.model_ports_by_type(mux_model, CIRCUIT_MODEL_PORT_INPUT, true);
/* We should have only 1 input port! */
VTR_ASSERT(1 == mux_input_ports.size());
/* Get the input port from MUX module */
ModulePortId module_input_port_id = module_manager.find_module_port(mux_module, circuit_lib.port_prefix(mux_input_ports[0]));
VTR_ASSERT(ModulePortId::INVALID() != module_input_port_id);
/* Get the port from module */
BasicPort module_input_port = module_manager.module_port(mux_module, module_input_port_id);
/* Iterate over all the inputs in the MUX graph */
for (const auto& input_node : mux_graph.inputs()) {
/* Fetch fundamental information from MUX graph w.r.t. the input node */
MuxInputId input_index = mux_graph.input_id(input_node);
VTR_ASSERT(MuxInputId::INVALID() != input_index);
/* For last input:
* Add a constant value to the last input, if this MUX needs a constant input
*/
if ( (MuxInputId(mux_graph.num_inputs() - 1) == mux_graph.input_id(input_node))
&& (true == circuit_lib.mux_add_const_input(mux_model)) ) {
/* Get the constant input value */
size_t const_value = circuit_lib.mux_const_input_value(mux_model);
VTR_ASSERT( (0 == const_value) || (1 == const_value) );
/* Instanciate a VDD module (default module)
* and build a net between VDD and the MUX input
*/
/* Get the moduleId for the buffer module */
ModuleId const_val_module_id = module_manager.find_module(generate_const_value_module_name(const_value));
/* We must have one */
VTR_ASSERT(ModuleId::INVALID() != const_val_module_id);
size_t const_val_instance = module_manager.num_instance(mux_module, const_val_module_id);
module_manager.add_child_module(mux_module, const_val_module_id);
ModulePortId const_port_id = module_manager.find_module_port(const_val_module_id, generate_const_value_module_output_port_name(const_value));
ModuleNetId input_net = module_manager.create_module_net(mux_module);
module_manager.add_module_net_source(mux_module, input_net, const_val_module_id, const_val_instance, const_port_id, 0);
mux_input_nets[input_index] = input_net;
continue;
}
/* When we do not need any buffer, create a net for the input directly */
if (false == circuit_lib.is_input_buffered(mux_model)) {
ModuleNetId input_net = module_manager.create_module_net(mux_module);
module_manager.add_module_net_source(mux_module, input_net, mux_module, 0, module_input_port_id, size_t(input_index));
mux_input_nets[input_index] = input_net;
continue;
}
/* Now we need to add intermediate buffers by instanciating the modules */
CircuitModelId buffer_model = circuit_lib.input_buffer_model(mux_model);
/* We must have a valid model id */
VTR_ASSERT(CircuitModelId::INVALID() != buffer_model);
/* Connect the module net from branch output to buffer input */
ModuleNetId buffer_net = module_manager.create_module_net(mux_module);
module_manager.add_module_net_source(mux_module, buffer_net, mux_module, 0, module_input_port_id, size_t(input_index));
/* Create a module net which sources from buffer output */
ModuleNetId input_net = add_inverter_buffer_child_module_and_nets(module_manager, mux_module, circuit_lib, buffer_model, buffer_net);
mux_input_nets[input_index] = input_net;
}
return mux_input_nets;
}
/*********************************************************************
* This function will add nets and input buffers (if needed)
* to a mux module
* Module net represents the connections when there are no output buffers
*
* mux_output_net[0]
* ------------+ |
* | v
* |--------> mux_output[0]
* |
* |
* Multiplexer | ...
* Strcuture |
* |--------> mux_output[i]
* | ^
* | |
* ------------+ mux_output_net[i]
*
* Module net represents the connections when there are output buffers
*
* mux_output_net[0]
* ------------+ |
* | |
* | v +------------------+
* |------->| output_buffer[0] |------> mux_output[0]
* | +------------------+
* |
* Multiplexer | ...
* Strcuture |
* | +------------------+
* |------->| output_buffer[i] |------> mux_output[i]
* | ^ +------------------+
* | |
* | |
* ------------+ mux_output_net[i]
*
*********************************************************************/
static
vtr::vector<MuxOutputId, ModuleNetId> build_mux_module_output_buffers(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const ModuleId& mux_module,
const CircuitModelId& mux_model,
const MuxGraph& mux_graph) {
/* Create module nets for output ports */
vtr::vector<MuxOutputId, ModuleNetId> mux_output_nets(mux_graph.num_outputs(), ModuleNetId::INVALID());
/* Get the output ports from the mux */
std::vector<CircuitPortId> mux_output_ports = circuit_lib.model_ports_by_type(mux_model, CIRCUIT_MODEL_PORT_OUTPUT, false);
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/* Iterate over all the outputs in the MUX module */
for (const auto& output_port : mux_output_ports) {
/* Get the output port from MUX module */
ModulePortId module_output_port_id = module_manager.find_module_port(mux_module, circuit_lib.port_prefix(output_port));
VTR_ASSERT(ModulePortId::INVALID() != module_output_port_id);
/* Get the port from module */
BasicPort module_output_port = module_manager.module_port(mux_module, module_output_port_id);
/* Iterate over each pin of the output port */
for (const size_t& pin : circuit_lib.pins(output_port)) {
/* Fetch fundamental information from MUX graph w.r.t. the input node */
/* Deposite the last level of the graph, which is a default value */
size_t output_node_level = mux_graph.num_node_levels() - 1;
/* If there is a fracturable level specified for the output, we find the exact level */
if (size_t(-1) != circuit_lib.port_lut_frac_level(output_port)) {
output_node_level = circuit_lib.port_lut_frac_level(output_port);
}
/* Deposite a zero, which is a default value */
size_t output_node_index_at_level = 0;
/* If there are output masks, we find the node_index */
if (!circuit_lib.port_lut_output_mask(output_port).empty()) {
output_node_index_at_level = circuit_lib.port_lut_output_mask(output_port).at(pin);
}
/* Double check the node exists in the Mux Graph */
MuxNodeId node_id = mux_graph.node_id(output_node_level, output_node_index_at_level);
VTR_ASSERT(MuxNodeId::INVALID() != node_id);
MuxOutputId output_index = mux_graph.output_id(node_id);
/* Create the port information of the module output at the given pin range, which is the output of buffer instance */
BasicPort instance_output_port(module_output_port.get_name(), pin, pin);
/* If the output is not supposed to be buffered, create a net for the input directly */
if (false == circuit_lib.is_output_buffered(mux_model)) {
ModuleNetId output_net = module_manager.create_module_net(mux_module);
module_manager.add_module_net_sink(mux_module, output_net, mux_module, 0, module_output_port_id, pin);
mux_output_nets[output_index] = output_net;
continue; /* Finish here */
}
/* Reach here, we need a buffer, create a port-to-port map and output the buffer instance */
/* Now we need to add intermediate buffers by instanciating the modules */
CircuitModelId buffer_model = circuit_lib.output_buffer_model(mux_model);
/* We must have a valid model id */
VTR_ASSERT(CircuitModelId::INVALID() != buffer_model);
/* Create a module net which sinks at buffer input */
ModuleNetId input_net = module_manager.create_module_net(mux_module);
ModuleNetId output_net = add_inverter_buffer_child_module_and_nets(module_manager, mux_module, circuit_lib, buffer_model, input_net);
module_manager.add_module_net_sink(mux_module, output_net, mux_module, 0, module_output_port_id, pin);
mux_output_nets[output_index] = input_net;
}
}
return mux_output_nets;
}
/*********************************************************************
* This function will
* 1. Build local encoders for a MUX module (if specified)
* 2. Build nets between memory ports of a MUX module and branch circuits
* This happens when local encoders are not needed
*
* MUX module
* +---------------------
* | mux_mem_nets/mux_mem_inv_nets
* | |
* | v +---------
* mem-+-------->|
* | | Branch Module
* | |
*
* 3. Build nets between local encoders and memory ports of a MUX module
* This happens when local encoders are needed
* 4. Build nets between local encoders and branch circuits
* This happens when local encoders are needed
*
* MUX module
* +---------------------
* |
* | +-------+ mux_mem_nets/mux_mem_inv_nets
* | | | |
* mem--+------>| | v +---------
* | | Local |-------->|
* | |Encoder| | Branch
* | | | | Module
* | | | |
* | | | |
*
*********************************************************************/
static
void build_mux_module_local_encoders_and_memory_nets(ModuleManager& module_manager,
const ModuleId& mux_module,
const CircuitLibrary& circuit_lib,
const CircuitModelId& mux_model,
const std::vector<CircuitPortId>& mux_sram_ports,
const MuxGraph& mux_graph,
vtr::vector<MuxMemId, ModuleNetId>& mux_mem_nets,
vtr::vector<MuxMemId, ModuleNetId>& mux_mem_inv_nets) {
/* Create nets here, and we will configure the net source later */
for (size_t mem = 0; mem < mux_graph.num_memory_bits(); ++mem) {
ModuleNetId mem_net = module_manager.create_module_net(mux_module);
mux_mem_nets.push_back(mem_net);
ModuleNetId mem_inv_net = module_manager.create_module_net(mux_module);
mux_mem_inv_nets.push_back(mem_inv_net);
}
if (false == circuit_lib.mux_use_local_encoder(mux_model)) {
/* Add mem and mem_inv nets here */
size_t mem_net_cnt = 0;
for (const auto& port : mux_sram_ports) {
ModulePortId mem_port_id = module_manager.find_module_port(mux_module, circuit_lib.port_prefix(port));
BasicPort mem_port = module_manager.module_port(mux_module, mem_port_id);
for (const size_t& pin : mem_port.pins()) {
MuxMemId mem_id = MuxMemId(mem_net_cnt);
/* Set the module net source */
module_manager.add_module_net_source(mux_module, mux_mem_nets[mem_id], mux_module, 0, mem_port_id, pin);
/* Update counter */
mem_net_cnt++;
}
}
VTR_ASSERT(mem_net_cnt == mux_graph.num_memory_bits());
/* Add mem and mem_inv nets here */
size_t mem_inv_net_cnt = 0;
for (const auto& port : mux_sram_ports) {
ModulePortId mem_inv_port_id = module_manager.find_module_port(mux_module, std::string(circuit_lib.port_prefix(port) + INV_PORT_POSTFIX));
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BasicPort mem_inv_port = module_manager.module_port(mux_module, mem_inv_port_id);
for (const size_t& pin : mem_inv_port.pins()) {
MuxMemId mem_id = MuxMemId(mem_inv_net_cnt);
/* Set the module net source */
module_manager.add_module_net_source(mux_module, mux_mem_inv_nets[mem_id], mux_module, 0, mem_inv_port_id, pin);
/* Update counter */
mem_inv_net_cnt++;
}
}
VTR_ASSERT(mem_inv_net_cnt == mux_graph.num_memory_bits());
return; /* Finish here if local encoders are not required */
}
/* Add local decoder instance here */
VTR_ASSERT(true == circuit_lib.mux_use_local_encoder(mux_model));
BasicPort decoder_data_port(generate_mux_local_decoder_data_port_name(), mux_graph.num_memory_bits());
BasicPort decoder_data_inv_port(generate_mux_local_decoder_data_inv_port_name(), mux_graph.num_memory_bits());
/* Local port to record the LSB and MSB of each level, here, we deposite (0, 0) */
ModulePortId mux_module_sram_port_id = module_manager.find_module_port(mux_module, circuit_lib.port_prefix(mux_sram_ports[0]));
ModulePortId mux_module_sram_inv_port_id = module_manager.find_module_port(mux_module, circuit_lib.port_prefix(mux_sram_ports[0]) + INV_PORT_POSTFIX);
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BasicPort lvl_addr_port(circuit_lib.port_prefix(mux_sram_ports[0]), 0);
BasicPort lvl_data_port(decoder_data_port.get_name(), 0);
BasicPort lvl_data_inv_port(decoder_data_inv_port.get_name(), 0);
/* Counter for mem index */
size_t mem_net_cnt = 0;
size_t mem_inv_net_cnt = 0;
for (const auto& lvl : mux_graph.levels()) {
size_t addr_size = find_mux_local_decoder_addr_size(mux_graph.num_memory_bits_at_level(lvl));
size_t data_size = mux_graph.num_memory_bits_at_level(lvl);
/* Update the LSB and MSB of addr and data port for the current level */
lvl_addr_port.rotate(addr_size);
lvl_data_port.rotate(data_size);
lvl_data_inv_port.rotate(data_size);
/* Exception: if the data size is one, we just need wires! */
if (1 == data_size) {
for (size_t pin_id = 0; pin_id < lvl_addr_port.pins().size(); ++pin_id) {
MuxMemId mem_id = MuxMemId(mem_net_cnt);
/* Set the module net source */
module_manager.add_module_net_source(mux_module, mux_mem_nets[mem_id], mux_module, 0, mux_module_sram_port_id, lvl_addr_port.pins()[pin_id]);
/* Update counter */
mem_net_cnt++;
MuxMemId mem_inv_id = MuxMemId(mem_inv_net_cnt);
/* Set the module net source */
module_manager.add_module_net_source(mux_module, mux_mem_inv_nets[mem_inv_id], mux_module, 0, mux_module_sram_inv_port_id, lvl_addr_port.pins()[pin_id]);
/* Update counter */
mem_inv_net_cnt++;
}
continue;
}
std::string decoder_module_name = generate_mux_local_decoder_subckt_name(addr_size, data_size);
ModuleId decoder_module = module_manager.find_module(decoder_module_name);
VTR_ASSERT(ModuleId::INVALID() != decoder_module);
size_t decoder_instance = module_manager.num_instance(mux_module, decoder_module);
module_manager.add_child_module(mux_module, decoder_module);
/* Add module nets to connect sram ports of MUX to address port */
ModulePortId decoder_module_addr_port_id = module_manager.find_module_port(decoder_module, generate_mux_local_decoder_addr_port_name());
BasicPort decoder_module_addr_port = module_manager.module_port(decoder_module, decoder_module_addr_port_id);
VTR_ASSERT(decoder_module_addr_port.get_width() == lvl_addr_port.get_width());
/* Build pin-to-pin net connection */
for (size_t pin_id = 0; pin_id < lvl_addr_port.pins().size(); ++pin_id) {
ModuleNetId net = module_manager.create_module_net(mux_module);
module_manager.add_module_net_source(mux_module, net, mux_module, 0, mux_module_sram_port_id, lvl_addr_port.pins()[pin_id]);
module_manager.add_module_net_sink(mux_module, net, decoder_module, decoder_instance, decoder_module_addr_port_id, decoder_module_addr_port.pins()[pin_id]);
}
/* Add module nets to connect data port to MUX mem ports */
ModulePortId decoder_module_data_port_id = module_manager.find_module_port(decoder_module, generate_mux_local_decoder_data_port_name());
BasicPort decoder_module_data_port = module_manager.module_port(decoder_module, decoder_module_data_port_id);
/* Build pin-to-pin net connection */
for (const size_t& pin : decoder_module_data_port.pins()) {
ModuleNetId net = mux_mem_nets[MuxMemId(mem_net_cnt)];
module_manager.add_module_net_source(mux_module, net, decoder_module, decoder_instance, decoder_module_data_port_id, pin);
/* Add the module nets to mux_mem_nets cache */
mem_net_cnt++;
}
ModulePortId decoder_module_data_inv_port_id = module_manager.find_module_port(decoder_module, generate_mux_local_decoder_data_inv_port_name());
BasicPort decoder_module_data_inv_port = module_manager.module_port(decoder_module, decoder_module_data_inv_port_id);
/* Build pin-to-pin net connection */
for (const size_t& pin : decoder_module_data_inv_port.pins()) {
ModuleNetId net = mux_mem_inv_nets[MuxMemId(mem_inv_net_cnt)];
module_manager.add_module_net_source(mux_module, net, decoder_module, decoder_instance, decoder_module_data_inv_port_id, pin);
/* Add the module nets to mux_mem_inv_nets cache */
mem_inv_net_cnt++;
}
}
VTR_ASSERT(mem_net_cnt == mux_graph.num_memory_bits());
VTR_ASSERT(mem_inv_net_cnt == mux_graph.num_memory_bits());
}
/*********************************************************************
* Generate module of a CMOS multiplexer with the given size
* The module will consist of three parts:
* 1. instances of the branch circuits of multiplexers which are generated before
* This builds up the multiplexing structure
* 2. Input buffers/inverters
* 3. Output buffers/inverters
*********************************************************************/
static
void build_cmos_mux_module(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const CircuitModelId& mux_model,
const std::string& module_name,
const MuxGraph& mux_graph) {
/* Get the global ports required by MUX (and any submodules) */
std::vector<CircuitPortId> mux_global_ports = circuit_lib.model_global_ports_by_type(mux_model, CIRCUIT_MODEL_PORT_INPUT, true, true);
/* Get the input ports from the mux */
std::vector<CircuitPortId> mux_input_ports = circuit_lib.model_ports_by_type(mux_model, CIRCUIT_MODEL_PORT_INPUT, true);
/* Get the output ports from the mux */
std::vector<CircuitPortId> mux_output_ports = circuit_lib.model_ports_by_type(mux_model, CIRCUIT_MODEL_PORT_OUTPUT, false);
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/* Get the sram ports from the mux
* Multiplexing structure does not mode_sram_ports, they are handled in LUT modules
* Here we just bypass it.
*/
std::vector<CircuitPortId> mux_sram_ports = find_circuit_regular_sram_ports(circuit_lib, mux_model);
/* Generate the Verilog netlist according to the mux_graph */
/* Find out the number of data-path inputs */
size_t num_inputs = find_mux_num_datapath_inputs(circuit_lib, mux_model, mux_graph.num_inputs());
/* Find out the number of outputs */
size_t num_outputs = mux_graph.num_outputs();
/* Find out the number of memory bits */
size_t num_mems = mux_graph.num_memory_bits();
/* The size of of memory ports depend on
* if a local encoder is used for the mux or not
* Multiplexer local encoders are applied to memory bits at each stage
*/
if (true == circuit_lib.mux_use_local_encoder(mux_model)) {
num_mems = 0;
for (const auto& lvl : mux_graph.levels()) {
size_t data_size = mux_graph.num_memory_bits_at_level(lvl);
num_mems += find_mux_local_decoder_addr_size(data_size);
}
}
/* Check codes to ensure the port of Verilog netlists will match */
/* MUX graph must have only 1 output */
VTR_ASSERT(1 == mux_input_ports.size());
/* A quick check on the model ports */
if ((CIRCUIT_MODEL_MUX == circuit_lib.model_type(mux_model))
|| ((CIRCUIT_MODEL_LUT == circuit_lib.model_type(mux_model))
&& (false == circuit_lib.is_lut_fracturable(mux_model))) ) {
VTR_ASSERT(1 == mux_output_ports.size());
VTR_ASSERT(1 == circuit_lib.port_size(mux_output_ports[0]));
} else {
VTR_ASSERT_SAFE( (CIRCUIT_MODEL_LUT == circuit_lib.model_type(mux_model))
&& (true == circuit_lib.is_lut_fracturable(mux_model)) );
for (const auto& port : mux_output_ports) {
VTR_ASSERT(0 < circuit_lib.port_size(port));
}
}
/* Create a Verilog Module based on the circuit model, and add to module manager */
ModuleId mux_module = module_manager.add_module(module_name);
VTR_ASSERT(ModuleId::INVALID() != mux_module);
/* Add module ports */
/* Add each input port
* Treat MUX and LUT differently
* 1. MUXes: we do not have a specific input/output sizes, it is inferred by architecture
* 2. LUTes: we do have specific input/output sizes,
* but the inputs of MUXes are the SRAM ports of LUTs
* and the SRAM ports of MUXes are the inputs of LUTs
*/
size_t input_port_cnt = 0;
for (const auto& port : mux_input_ports) {
BasicPort input_port(circuit_lib.port_prefix(port), num_inputs);
module_manager.add_port(mux_module, input_port, ModuleManager::MODULE_INPUT_PORT);
/* Update counter */
input_port_cnt++;
}
/* Double check: We should have only 1 input port generated here! */
VTR_ASSERT(1 == input_port_cnt);
/* Add input buffers and update module nets for inputs */
vtr::vector<MuxInputId, ModuleNetId> mux_input_nets = build_mux_module_input_buffers(module_manager, circuit_lib, mux_module, mux_model, mux_graph);
for (const auto& port : mux_output_ports) {
BasicPort output_port(circuit_lib.port_prefix(port), num_outputs);
if (CIRCUIT_MODEL_LUT == circuit_lib.model_type(mux_model)) {
output_port.set_width(circuit_lib.port_size(port));
}
module_manager.add_port(mux_module, output_port, ModuleManager::MODULE_OUTPUT_PORT);
}
/* TODO: Add output buffers and update module nets for outputs */
vtr::vector<MuxOutputId, ModuleNetId> mux_output_nets = build_mux_module_output_buffers(module_manager, circuit_lib, mux_module, mux_model, mux_graph);
size_t sram_port_cnt = 0;
for (const auto& port : mux_sram_ports) {
BasicPort mem_port(circuit_lib.port_prefix(port), num_mems);
module_manager.add_port(mux_module, mem_port, ModuleManager::MODULE_INPUT_PORT);
BasicPort mem_inv_port(std::string(circuit_lib.port_prefix(port) + INV_PORT_POSTFIX), num_mems);
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module_manager.add_port(mux_module, mem_inv_port, ModuleManager::MODULE_INPUT_PORT);
/* Update counter */
sram_port_cnt++;
}
VTR_ASSERT(1 == sram_port_cnt);
/* Create module nets for mem and mem_inv ports */
vtr::vector<MuxMemId, ModuleNetId> mux_mem_nets;
vtr::vector<MuxMemId, ModuleNetId> mux_mem_inv_nets;
build_mux_module_local_encoders_and_memory_nets(module_manager, mux_module,
circuit_lib, mux_model, mux_sram_ports,
mux_graph,
mux_mem_nets, mux_mem_inv_nets);
/* Print the internal logic in Verilog codes */
/* Print the Multiplexing structure in Verilog codes
* Separated generation strategy on using standard cell MUX2 or TGATE,
* 1. MUX2 has a fixed port map: input_port[0] and input_port[1] is the data_path input
* 2. Branch TGATE-based module has a fixed port name
* TODO: the naming could be more flexible?
*/
/* Get the tgate model */
CircuitModelId tgate_model = circuit_lib.pass_gate_logic_model(mux_model);
/* Instanciate the branch module:
* Case 1: the branch module is a standard cell MUX2
* Case 2: the branch module is a tgate-based module
*/
std::string branch_module_name;
if (CIRCUIT_MODEL_GATE == circuit_lib.model_type(tgate_model)) {
VTR_ASSERT(CIRCUIT_MODEL_GATE_MUX2 == circuit_lib.gate_type(tgate_model));
build_cmos_mux_module_mux2_multiplexing_structure(module_manager, circuit_lib, mux_module, mux_model, tgate_model, mux_input_nets, mux_output_nets, mux_mem_nets, mux_graph);
} else {
VTR_ASSERT(CIRCUIT_MODEL_PASSGATE == circuit_lib.model_type(tgate_model));
build_cmos_mux_module_tgate_multiplexing_structure(module_manager, circuit_lib, mux_module, mux_model, mux_input_nets, mux_output_nets, mux_mem_nets, mux_mem_inv_nets, mux_graph);
}
/* Add global ports to the pb_module:
* This is a much easier job after adding sub modules (instances),
* we just need to find all the global ports from the child modules and build a list of it
*/
add_module_global_ports_from_child_modules(module_manager, mux_module);
}
/*********************************************************************
* Generate a module of a RRAM-based multiplexer with the given size
* The module will consist of three parts:
* 1. instances of the branch circuits of multiplexers which are generated before
* This builds up the 4T1R-based multiplexing structure
*
* BLB WL
* | | ...
* v v
* +--------+
* in[0]-->| | BLB WL
* ...| Branch |-----+ | |
* in -->| 0 | | v v
* [N-1] +--------+ | +--------+
* ... -->| |
* BLBs WLs ...| Branch |
* | | ... -->| X |
* v v +--------+
* +--------+ |
* -->| | |
* ...| Branch |----+
* -->| i |
* +--------+
*
* 2. Input buffers/inverters
* 3. Output buffers/inverters
*********************************************************************/
static
void build_rram_mux_module(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const CircuitModelId& circuit_model,
const std::string& module_name,
const MuxGraph& mux_graph) {
/* Error out for the conditions where we are not yet supported! */
if (CIRCUIT_MODEL_LUT == circuit_lib.model_type(circuit_model)) {
/* RRAM LUT is not supported now... */
VTR_LOGF_ERROR(__FILE__, __LINE__, "RRAM-based LUT is not supported for circuit model '%s')!\n",
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circuit_lib.model_name(circuit_model).c_str());
exit(1);
}
/* Get the global ports required by MUX (and any submodules) */
std::vector<CircuitPortId> mux_global_ports = circuit_lib.model_global_ports_by_type(circuit_model, CIRCUIT_MODEL_PORT_INPUT, true, true);
/* Get the input ports from the mux */
std::vector<CircuitPortId> mux_input_ports = circuit_lib.model_ports_by_type(circuit_model, CIRCUIT_MODEL_PORT_INPUT, true);
/* Get the output ports from the mux */
std::vector<CircuitPortId> mux_output_ports = circuit_lib.model_ports_by_type(circuit_model, CIRCUIT_MODEL_PORT_OUTPUT, true);
/* Get the BL and WL ports from the mux */
std::vector<CircuitPortId> mux_blb_ports = circuit_lib.model_ports_by_type(circuit_model, CIRCUIT_MODEL_PORT_BLB, true);
std::vector<CircuitPortId> mux_wl_ports = circuit_lib.model_ports_by_type(circuit_model, CIRCUIT_MODEL_PORT_WL, true);
/* Generate the Verilog netlist according to the mux_graph */
/* Find out the number of data-path inputs */
size_t num_inputs = find_mux_num_datapath_inputs(circuit_lib, circuit_model, mux_graph.num_inputs());
/* Find out the number of outputs */
size_t num_outputs = mux_graph.num_outputs();
/* Find out the number of memory bits */
size_t num_mems = mux_graph.num_memory_bits();
/* Check codes to ensure the port of Verilog netlists will match */
/* MUX graph must have only 1 input and 1 BLB and 1 WL port */
VTR_ASSERT(1 == mux_input_ports.size());
VTR_ASSERT(1 == mux_blb_ports.size());
VTR_ASSERT(1 == mux_wl_ports.size());
/* Create a Verilog Module based on the circuit model, and add to module manager */
ModuleId module_id = module_manager.add_module(module_name);
VTR_ASSERT(ModuleId::INVALID() != module_id);
/* Add module ports */
/* Add each global port */
for (const auto& port : mux_global_ports) {
/* Configure each global port */
BasicPort global_port(circuit_lib.port_prefix(port), circuit_lib.port_size(port));
module_manager.add_port(module_id, global_port, ModuleManager::MODULE_GLOBAL_PORT);
}
/* Add each input port */
size_t input_port_cnt = 0;
for (const auto& port : mux_input_ports) {
BasicPort input_port(circuit_lib.port_prefix(port), num_inputs);
module_manager.add_port(module_id, input_port, ModuleManager::MODULE_INPUT_PORT);
/* Update counter */
input_port_cnt++;
}
/* Double check: We should have only 1 input port generated here! */
VTR_ASSERT(1 == input_port_cnt);
for (const auto& port : mux_output_ports) {
BasicPort output_port(circuit_lib.port_prefix(port), num_outputs);
if (CIRCUIT_MODEL_LUT == circuit_lib.model_type(circuit_model)) {
output_port.set_width(circuit_lib.port_size(port));
}
module_manager.add_port(module_id, output_port, ModuleManager::MODULE_OUTPUT_PORT);
}
/* BLB port */
for (const auto& port : mux_blb_ports) {
/* IMPORTANT: RRAM-based MUX has an additional BLB pin per level
* So, the actual port width of BLB should be added by the number of levels of the MUX graph
*/
BasicPort blb_port(circuit_lib.port_prefix(port), num_mems + mux_graph.num_levels());
module_manager.add_port(module_id, blb_port, ModuleManager::MODULE_INPUT_PORT);
}
/* WL port */
for (const auto& port : mux_wl_ports) {
/* IMPORTANT: RRAM-based MUX has an additional WL pin per level
* So, the actual port width of WL should be added by the number of levels of the MUX graph
*/
BasicPort wl_port(circuit_lib.port_prefix(port), num_mems + mux_graph.num_levels());
module_manager.add_port(module_id, wl_port, ModuleManager::MODULE_INPUT_PORT);
}
/* TODO: Add the input and output buffers in Verilog codes */
/* TODO: Print the internal logic in Verilog codes */
}
/***********************************************
* Generate Verilog codes modeling a multiplexer
* with the given graph-level description
**********************************************/
static
void build_mux_module(ModuleManager& module_manager,
const CircuitLibrary& circuit_lib,
const CircuitModelId& circuit_model,
const MuxGraph& mux_graph) {
std::string module_name = generate_mux_subckt_name(circuit_lib, circuit_model,
find_mux_num_datapath_inputs(circuit_lib, circuit_model, mux_graph.num_inputs()),
std::string(""));
/* Multiplexers built with different technology is in different organization */
switch (circuit_lib.design_tech_type(circuit_model)) {
case CIRCUIT_MODEL_DESIGN_CMOS:
/* SRAM-based Multiplexer Verilog module generation */
build_cmos_mux_module(module_manager, circuit_lib, circuit_model, module_name, mux_graph);
break;
case CIRCUIT_MODEL_DESIGN_RRAM:
/* TODO: RRAM-based Multiplexer Verilog module generation */
build_rram_mux_module(module_manager, circuit_lib, circuit_model, module_name, mux_graph);
break;
default:
VTR_LOGF_ERROR(__FILE__, __LINE__, "Invalid design technology of multiplexer '%s'\n",
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circuit_lib.model_name(circuit_model).c_str());
exit(1);
}
}
/***********************************************
* Generate Verilog modules for all the unique
* multiplexers in the FPGA device
**********************************************/
void build_mux_modules(ModuleManager& module_manager,
const MuxLibrary& mux_lib,
const CircuitLibrary& circuit_lib) {
vtr::ScopedStartFinishTimer timer("Building multiplexer modules");
/* Generate basis sub-circuit for unique branches shared by the multiplexers */
for (auto mux : mux_lib.muxes()) {
const MuxGraph& mux_graph = mux_lib.mux_graph(mux);
CircuitModelId mux_circuit_model = mux_lib.mux_circuit_model(mux);
/* Create a mux graph for the branch circuit */
std::vector<MuxGraph> branch_mux_graphs = mux_graph.build_mux_branch_graphs();
/* Create branch circuits, which are N:1 one-level or 2:1 tree-like MUXes */
for (auto branch_mux_graph : branch_mux_graphs) {
build_mux_branch_module(module_manager, circuit_lib, mux_circuit_model,
find_mux_num_datapath_inputs(circuit_lib, mux_circuit_model, mux_graph.num_inputs()),
branch_mux_graph);
}
}
/* Generate unique Verilog modules for the multiplexers */
for (auto mux : mux_lib.muxes()) {
const MuxGraph& mux_graph = mux_lib.mux_graph(mux);
CircuitModelId mux_circuit_model = mux_lib.mux_circuit_model(mux);
/* Create MUX circuits */
build_mux_module(module_manager, circuit_lib, mux_circuit_model, mux_graph);
}
}
} /* end namespace openfpga */