yosys/passes/memory/memory_memx.cc

93 lines
3.2 KiB
C++

/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2012 Clifford Wolf <clifford@clifford.at>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#include "kernel/register.h"
#include "kernel/log.h"
#include <sstream>
#include <set>
#include <stdlib.h>
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
struct MemoryMemxPass : public Pass {
MemoryMemxPass() : Pass("memory_memx", "emulate vlog sim behavior for mem ports") { }
void help() override
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" memory_memx [selection]\n");
log("\n");
log("This pass adds additional circuitry that emulates the Verilog simulation\n");
log("behavior for out-of-bounds memory reads and writes.\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override {
log_header(design, "Executing MEMORY_MEMX pass (converting $mem cells to logic and flip-flops).\n");
extra_args(args, 1, design);
for (auto module : design->selected_modules())
{
vector<Cell*> mem_port_cells;
for (auto cell : module->selected_cells())
if (cell->type.in(ID($memrd), ID($memwr)))
mem_port_cells.push_back(cell);
for (auto cell : mem_port_cells)
{
IdString memid = cell->getParam(ID::MEMID).decode_string();
RTLIL::Memory *mem = module->memories.at(memid);
int lowest_addr = mem->start_offset;
int highest_addr = mem->start_offset + mem->size - 1;
SigSpec addr = cell->getPort(ID::ADDR);
addr.extend_u0(32);
SigSpec addr_ok = module->Nex(NEW_ID, module->ReduceXor(NEW_ID, addr), module->ReduceXor(NEW_ID, {addr, State::S1}));
if (lowest_addr != 0)
addr_ok = module->LogicAnd(NEW_ID, addr_ok, module->Ge(NEW_ID, addr, lowest_addr));
addr_ok = module->LogicAnd(NEW_ID, addr_ok, module->Le(NEW_ID, addr, highest_addr));
if (cell->type == ID($memrd))
{
if (cell->getParam(ID::CLK_ENABLE).as_bool())
log_error("Cell %s.%s (%s) has an enabled clock. Clocked $memrd cells are not supported by memory_memx!\n",
log_id(module), log_id(cell), log_id(cell->type));
SigSpec rdata = cell->getPort(ID::DATA);
Wire *raw_rdata = module->addWire(NEW_ID, GetSize(rdata));
module->addMux(NEW_ID, SigSpec(State::Sx, GetSize(rdata)), raw_rdata, addr_ok, rdata);
cell->setPort(ID::DATA, raw_rdata);
}
if (cell->type == ID($memwr))
{
SigSpec en = cell->getPort(ID::EN);
en = module->And(NEW_ID, en, addr_ok.repeat(GetSize(en)));
cell->setPort(ID::EN, en);
}
}
}
}
} MemoryMemxPass;
PRIVATE_NAMESPACE_END