From ec2a468bd389a8275a9a2584fb475901cc495d03 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marcelina=20Ko=C5=9Bcielnicka?= Date: Tue, 25 May 2021 23:42:58 +0200 Subject: [PATCH] backend/verilog: Add alternate mode for transparent read port output. This mode will be used whenever read port cannot be handled in the "extract address register" way, ie. whenever it has enable, reset, init functionality or (in the future) mixed transparency mask. --- backends/verilog/verilog_backend.cc | 72 ++++++++++++++++++++++++++++- 1 file changed, 71 insertions(+), 1 deletion(-) diff --git a/backends/verilog/verilog_backend.cc b/backends/verilog/verilog_backend.cc index b363bc2fe..8f96c3a58 100644 --- a/backends/verilog/verilog_backend.cc +++ b/backends/verilog/verilog_backend.cc @@ -553,7 +553,17 @@ void dump_memory(std::ostream &f, std::string indent, Mem &mem) clk_to_arst_cond[clk_domain_str] = os2.str(); } } - if (!port.transparent) + + // Decide how to represent the transparency; same idea as Mem::extract_rdff. + bool trans_use_addr = port.transparent; + + if (GetSize(mem.wr_ports) == 0) + trans_use_addr = false; + + if (port.en != State::S1 || port.srst != State::S0 || port.arst != State::S0 || !port.init_value.is_fully_undef()) + trans_use_addr = false; + + if (!trans_use_addr) { // for clocked read ports make something like: // reg [..] temp_id; @@ -618,6 +628,66 @@ void dump_memory(std::ostream &f, std::string indent, Mem &mem) clk_to_lof_body[clk_domain_str].push_back(os.str()); } + for (int i = 0; i < GetSize(mem.wr_ports); i++) { + auto &wport = mem.wr_ports[i]; + if (!port.transparent) + continue; + if (!wport.clk_enable) + continue; + if (wport.clk != port.clk) + continue; + if (wport.clk_polarity != port.clk_polarity) + continue; + int min_wide_log2 = std::min(port.wide_log2, wport.wide_log2); + int max_wide_log2 = std::max(port.wide_log2, wport.wide_log2); + bool wide_write = wport.wide_log2 > port.wide_log2; + for (int sub = 0; sub < (1 << max_wide_log2); sub += (1 << min_wide_log2)) { + SigSpec raddr = port.addr; + SigSpec waddr = wport.addr; + if (wide_write) + waddr = wport.sub_addr(sub); + else + raddr = port.sub_addr(sub); + int pos = 0; + int ewidth = mem.width << min_wide_log2; + int wsub = wide_write ? sub : 0; + int rsub = wide_write ? 0 : sub; + while (pos < ewidth) { + int epos = pos; + while (epos < ewidth && wport.en[epos + wsub * mem.width] == wport.en[pos + wsub * mem.width]) + epos++; + + std::ostringstream os; + if (has_indent) + os << indent; + os << "if ("; + dump_sigspec(os, wport.en[pos + wsub * mem.width]); + if (raddr != waddr) { + os << " && "; + dump_sigspec(os, raddr); + os << " == "; + dump_sigspec(os, waddr); + } + os << ")\n"; + clk_to_lof_body[clk_domain_str].push_back(os.str()); + + std::ostringstream os2; + if (has_indent) + os2 << indent; + os2 << indent; + os2 << temp_id; + if (epos-pos != GetSize(port.data)) + os2 << stringf("[%d:%d]", rsub * mem.width + epos-1, rsub * mem.width + pos); + os2 << " <= "; + dump_sigspec(os2, wport.data.extract(wsub * mem.width + pos, epos-pos)); + os2 << ";\n"; + clk_to_lof_body[clk_domain_str].push_back(os2.str()); + + pos = epos; + } + } + } + if (port.srst != State::S0 && port.ce_over_srst) { std::ostringstream os; -- 2.30.2