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Verilog backend for $mem cells should now be able to handle different 

write-enable bits and RD_TRANSPARENT parameter settings.
This commit is contained in:
luke whittlesey 2015-05-08 15:29:51 -04:00
parent c0b68f4848
commit 2c1e150297
1 changed files with 105 additions and 50 deletions
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155
backends/verilog/verilog_backend.cc
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@ -29,10 +29,12 @@
#include "kernel/register.h" #include "kernel/register.h"
#include "kernel/celltypes.h" #include "kernel/celltypes.h"
#include "kernel/log.h" #include "kernel/log.h"
#include "kernel/sigtools.h"
#include <string> #include <string>
#include <sstream> #include <sstream>
#include <set> #include <set>
#include <map> #include <map>
#include <ctime>
USING_YOSYS_NAMESPACE USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN PRIVATE_NAMESPACE_BEGIN
@ -151,6 +153,17 @@ bool is_reg_wire(RTLIL::SigSpec sig, std::string &reg_name)
return true; return true;
} }
bool bit_check_equal(SigMap &sigmap, RTLIL::SigSpec &a, RTLIL::SigSpec &b)
{
if (a.is_fully_const() && b.is_fully_const()){
return (a.as_bool() == b.as_bool());
}else if (!a.is_fully_const() && !b.is_fully_const()){
return (sigmap(a) == sigmap(b));
}else{
return false;
}
}
void dump_const(std::ostream &f, const RTLIL::Const &data, int width = -1, int offset = 0, bool no_decimal = false, bool set_signed = false, bool escape_comment = false) void dump_const(std::ostream &f, const RTLIL::Const &data, int width = -1, int offset = 0, bool no_decimal = false, bool set_signed = false, bool escape_comment = false)
{ {
if (width < 0) if (width < 0)
@ -790,7 +803,6 @@ bool dump_cell_expr(std::ostream &f, std::string indent, RTLIL::Cell *cell)
if (cell->type == "$mem") if (cell->type == "$mem")
{ {
std::ostringstream os;
RTLIL::IdString memid = cell->parameters["\\MEMID"].decode_string(); RTLIL::IdString memid = cell->parameters["\\MEMID"].decode_string();
std::string mem_id = id( cell->parameters["\\MEMID"].decode_string() ); std::string mem_id = id( cell->parameters["\\MEMID"].decode_string() );
int abits = cell->parameters["\\ABITS"].as_int(); int abits = cell->parameters["\\ABITS"].as_int();
@ -810,22 +822,22 @@ bool dump_cell_expr(std::ostream &f, std::string indent, RTLIL::Cell *cell)
memory.width = width; memory.width = width;
memory.start_offset = offset; memory.start_offset = offset;
memory.size = size; memory.size = size;
dump_memory(os, indent.c_str(), &memory); dump_memory(f, indent.c_str(), &memory);
if (use_init) if (use_init)
{ {
os << stringf("%s" "initial begin\n", indent.c_str()); f << stringf("%s" "initial begin\n", indent.c_str());
for (int i=0; i<size; i++) for (int i=0; i<size; i++)
{ {
mem_val = cell->parameters["\\INIT"].extract(i*width, width).as_int(); mem_val = cell->parameters["\\INIT"].extract(i*width, width).as_int();
os << stringf("%s" " %s[%d] <= %d'd%d;\n", indent.c_str(), mem_id.c_str(), i, width, mem_val); f << stringf("%s" " %s[%d] <= %d'd%d;\n", indent.c_str(), mem_id.c_str(), i, width, mem_val);
} }
os << stringf("%s" "end\n", indent.c_str()); f << stringf("%s" "end\n", indent.c_str());
} }
int nread_ports = cell->parameters["\\RD_PORTS"].as_int(); int nread_ports = cell->parameters["\\RD_PORTS"].as_int();
RTLIL::SigSpec sig_rd_clk, sig_rd_data, sig_rd_addr; RTLIL::SigSpec sig_rd_clk, sig_rd_data, sig_rd_addr;
bool use_rd_clk, rd_clk_posedge; bool use_rd_clk, rd_clk_posedge, rd_transparent;
RTLIL::IdString new_id;
// read ports // read ports
for (int i=0; i < nread_ports; i++) for (int i=0; i < nread_ports; i++)
{ {
@ -834,33 +846,58 @@ bool dump_cell_expr(std::ostream &f, std::string indent, RTLIL::Cell *cell)
sig_rd_addr = cell->getPort("\\RD_ADDR").extract(i*abits, abits); sig_rd_addr = cell->getPort("\\RD_ADDR").extract(i*abits, abits);
use_rd_clk = cell->parameters["\\RD_CLK_ENABLE"].extract(i).as_bool(); use_rd_clk = cell->parameters["\\RD_CLK_ENABLE"].extract(i).as_bool();
rd_clk_posedge = cell->parameters["\\RD_CLK_POLARITY"].extract(i).as_bool(); rd_clk_posedge = cell->parameters["\\RD_CLK_POLARITY"].extract(i).as_bool();
if (use_rd_clk) rd_transparent = cell->parameters["\\RD_TRANSPARENT"].extract(i).as_bool();
if (use_rd_clk && !rd_transparent)
{ {
// for clocked read ports make something like: // for clocked read ports make something like:
// always @(posedge clk) // always @(posedge clk)
// r_data <= array_reg[r_addr]; // r_data <= array_reg[r_addr];
os << stringf("%s" "always @(%sedge ", indent.c_str(), rd_clk_posedge ? "pos" : "neg"); f << stringf("%s" "always @(%sedge ", indent.c_str(), rd_clk_posedge ? "pos" : "neg");
dump_sigspec(os, sig_rd_clk); dump_sigspec(f, sig_rd_clk);
os << stringf(")\n"); f << stringf(")\n");
os << stringf("%s" " ", indent.c_str()); f << stringf("%s" " ", indent.c_str());
dump_sigspec(os, sig_rd_data); dump_sigspec(f, sig_rd_data);
os << stringf(" <= %s[", mem_id.c_str()); f << stringf(" <= %s[", mem_id.c_str());
dump_sigspec(os, sig_rd_addr); dump_sigspec(f, sig_rd_addr);
os << stringf("];\n"); f << stringf("];\n");
}else{ }else{
// for non-clocked read-ports make something like: if (rd_transparent){
// assign r_data = array_reg[r_addr]; // for rd-transparent read-ports make something like:
os << stringf("%s" "assign ", indent.c_str()); // reg [..] new-id;
dump_sigspec(os, sig_rd_data); // always @(posedge clk)
os << stringf(" = %s[", mem_id.c_str()); // new-id <= r_addr;
dump_sigspec(os, sig_rd_addr); // assign r_data = array_reg[new-id];
os << stringf("];\n"); new_id = RTLIL::IdString(stringf("$%d", (int)time(NULL)));
reset_auto_counter_id(new_id, true);
f << stringf("%s" "reg [%d:0] %s;\n", indent.c_str(), sig_rd_addr.size() - 1, id(new_id).c_str());
f << stringf("%s" "always @(%sedge ", indent.c_str(), rd_clk_posedge ? "pos" : "neg");
dump_sigspec(f, sig_rd_clk);
f << stringf(")\n");
f << stringf("%s" " %s <= ", indent.c_str(), id(new_id).c_str());
dump_sigspec(f, sig_rd_addr);
f << stringf(";\n");
f << stringf("%s" "assign ", indent.c_str());
dump_sigspec(f, sig_rd_data);
f << stringf(" = %s[%s];\n", mem_id.c_str(), id(new_id).c_str());
}else{
// for non-clocked read-ports make something like:
// assign r_data = array_reg[r_addr];
f << stringf("%s" "assign ", indent.c_str());
dump_sigspec(f, sig_rd_data);
f << stringf(" = %s[", mem_id.c_str());
dump_sigspec(f, sig_rd_addr);
f << stringf("];\n");
}
} }
} }
int nwrite_ports = cell->parameters["\\WR_PORTS"].as_int(); int nwrite_ports = cell->parameters["\\WR_PORTS"].as_int();
RTLIL::SigSpec sig_wr_clk, sig_wr_data, sig_wr_addr, sig_wr_en, sig_wr_en_bit, temp_wire; RTLIL::SigSpec sig_wr_clk, sig_wr_data, sig_wr_addr, sig_wr_en, sig_wr_en_bit, last_bit, current_bit;
bool wr_clk_posedge, use_wen; bool wr_clk_posedge; //, use_wen; //, use_individual_wen_bits;
std::vector<RTLIL::SigSpec> lof_wen;
std::map<RTLIL::SigSpec, int> wen_to_width;
SigMap sigmap(active_module);
int n, wen_width;
// write ports // write ports
for (int i=0; i < nwrite_ports; i++) for (int i=0; i < nwrite_ports; i++)
{ {
@ -874,36 +911,54 @@ bool dump_cell_expr(std::ostream &f, std::string indent, RTLIL::Cell *cell)
sig_wr_en = cell->getPort("\\WR_EN").extract(i*width, width); sig_wr_en = cell->getPort("\\WR_EN").extract(i*width, width);
sig_wr_en_bit = sig_wr_en.extract(0); sig_wr_en_bit = sig_wr_en.extract(0);
wr_clk_posedge = cell->parameters["\\WR_CLK_POLARITY"].extract(i).as_bool(); wr_clk_posedge = cell->parameters["\\WR_CLK_POLARITY"].extract(i).as_bool();
use_wen = !(sig_wr_en.is_fully_const() && (sig_wr_en.as_int() == ((1 << width) - 1))); // group the wen bits
// if we're using wen, make sure every bit is the same wire, otherwise this verilog description won't be correct last_bit = sig_wr_en.extract(0);
// question: when would WR_EN have different wires for each bit? lof_wen.push_back(last_bit);
if (sig_wr_en_bit.size() != 1) wen_to_width[last_bit] = 0;
return false; for(int j=0; j<width; j++)
if (use_wen)
{ {
for(int j=0; j<width; j++) current_bit = sig_wr_en.extract(j);
{ if ( bit_check_equal(sigmap, current_bit, last_bit) ){
temp_wire = sig_wr_en.extract(j); wen_to_width[lof_wen.back()] += 1;
if ( (temp_wire.size() != 1) || !(temp_wire.is_chunk() && (temp_wire.as_chunk().wire->name == sig_wr_en_bit.as_chunk().wire->name)) ) }else{
return false; lof_wen.push_back(current_bit);
wen_to_width[current_bit] = 1;
} }
last_bit = current_bit;
} }
os << stringf("%s" "always @(%sedge ", indent.c_str(), wr_clk_posedge ? "pos" : "neg"); // make something like:
dump_sigspec(os, sig_wr_clk); // always @(posedge clk)
os << stringf(")\n"); // if (wr_en_bit)
if (use_wen) // memid[w_addr][??] <= w_data[??];
{ // ...
os << stringf("%s" " if (", indent.c_str()); n = 0;
dump_sigspec(os, sig_wr_en_bit); for (auto &wen_bit : lof_wen) {
os << stringf(")\n "); wen_width = wen_to_width[wen_bit];
if (!wen_bit.is_fully_zero())
{
f << stringf("%s" "always @(%sedge ", indent.c_str(), wr_clk_posedge ? "pos" : "neg");
dump_sigspec(f, sig_wr_clk);
f << stringf(")\n");
//if (wen_bit.is_wire()) // why doesn't wen_bit.is_wire() work here?
if (!wen_bit.has_const())
{
f << stringf("%s" " if (", indent.c_str());
dump_sigspec(f, wen_bit);
f << stringf(")\n ");
}
f << stringf("%s" " %s[", indent.c_str(), mem_id.c_str());
dump_sigspec(f, sig_wr_addr);
if (wen_width == width)
f << stringf("] <= ");
else
f << stringf("][%d:%d] <= ", n+wen_width-1, n);
dump_sigspec(f, sig_wr_data.extract(n, wen_width));
f << stringf(";\n");
}
n += wen_width;
} }
os << stringf("%s" " %s[", indent.c_str(), mem_id.c_str());
dump_sigspec(os, sig_wr_addr);
os << stringf("] <= ");
dump_sigspec(os, sig_wr_data);
os << stringf(";\n");
} }
f << os.str();
return true; return true;
} }