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More support code for $sr cells

This commit is contained in:
Clifford Wolf 2013-03-14 11:15:00 +01:00
parent de823ce964
commit 11789db206
2 changed files with 50 additions and 1 deletions
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30
backends/verilog/verilog_backend.cc
View File

@ -143,7 +143,7 @@ bool is_reg_wire(RTLIL::SigSpec sig, std::string &reg_name)
if (sig.width == 1)
reg_name += stringf("[%d]", sig.chunks[0].wire->start_offset + sig.chunks[0].offset);
else
reg_name += stringf("[%d]", sig.chunks[0].wire->start_offset + sig.chunks[0].offset + sig.chunks[0].width - 1,
reg_name += stringf("[%d:%d]", sig.chunks[0].wire->start_offset + sig.chunks[0].offset + sig.chunks[0].width - 1,
sig.chunks[0].wire->start_offset + sig.chunks[0].offset);
}
return true;
@ -556,6 +556,33 @@ bool dump_cell_expr(FILE *f, std::string indent, RTLIL::Cell *cell)
return true;
}
if (cell->type == "$sr")
{
RTLIL::SigSpec sig_set, sig_reset;
std::string reg_name = cellname(cell);
bool out_is_reg_wire = is_reg_wire(cell->connections["\\Q"], reg_name);
if (!out_is_reg_wire)
fprintf(f, "%s" "reg [%d:0] %s;\n", indent.c_str(), cell->parameters["\\WIDTH"].as_int()-1, reg_name.c_str());
fprintf(f, "%s" "always @*\n", indent.c_str());
fprintf(f, "%s" " %s <= (%s | ", indent.c_str(), reg_name.c_str(), reg_name.c_str());
dump_cell_expr_port(f, cell, "S", false);
fprintf(f, ") & ~");
dump_cell_expr_port(f, cell, "R", false);
fprintf(f, ";\n");
if (!out_is_reg_wire) {
fprintf(f, "%s" "assign ", indent.c_str());
dump_sigspec(f, cell->connections["\\Q"]);
fprintf(f, " = %s;\n", reg_name.c_str());
}
return true;
}
// FIXME: $memrd, $memwr, $mem, $fsm
return false;
@ -891,6 +918,7 @@ struct VerilogBackend : public Backend {
reg_ct.clear();
reg_ct.setup_stdcells_mem();
reg_ct.cell_types.insert("$sr");
reg_ct.cell_types.insert("$dff");
reg_ct.cell_types.insert("$adff");

21
techlibs/simlib.v
View File

@ -642,6 +642,27 @@ endmodule
// --------------------------------------------------------
module \$sr (S, R, Q);
parameter WIDTH = 0;
input CLK;
input [WIDTH-1:0] S, R;
output reg [WIDTH-1:0] Q;
integer i;
always @(S, R)
for (i = 0; i < WIDTH; i = i+1) begin
if (R[i])
Q[i] <= 0;
else if (S[i])
Q[i] <= 1;
end
endmodule
// --------------------------------------------------------
module \$dff (CLK, D, Q);
parameter WIDTH = 0;