diff options
Diffstat (limited to 'techlibs/common')
| -rw-r--r-- | techlibs/common/cmp2lut.v | 2 | ||||
| -rw-r--r-- | techlibs/common/simcells.v | 19 | ||||
| -rw-r--r-- | techlibs/common/simlib.v | 44 | ||||
| -rw-r--r-- | techlibs/common/synth.cc | 21 |
4 files changed, 72 insertions, 14 deletions
diff --git a/techlibs/common/cmp2lut.v b/techlibs/common/cmp2lut.v index 8aa1eb957..0d0757767 100644 --- a/techlibs/common/cmp2lut.v +++ b/techlibs/common/cmp2lut.v @@ -27,7 +27,7 @@ parameter _TECHMAP_CONSTVAL_A_ = 0; parameter _TECHMAP_CONSTMSK_B_ = 0; parameter _TECHMAP_CONSTVAL_B_ = 0; -function automatic integer gen_lut; +function automatic [(1 << `LUT_WIDTH)-1:0] gen_lut; input integer width; input integer operation; input integer swap; diff --git a/techlibs/common/simcells.v b/techlibs/common/simcells.v index 289673e82..64720e598 100644 --- a/techlibs/common/simcells.v +++ b/techlibs/common/simcells.v @@ -230,6 +230,25 @@ endmodule // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| //- +//- $_NMUX_ (A, B, S, Y) +//- +//- A 2-input inverting MUX gate. +//- +//- Truth table: A B S | Y +//- -------+--- +//- 0 - 0 | 1 +//- 1 - 0 | 0 +//- - 0 1 | 1 +//- - 1 1 | 0 +//- +module \$_NMUX_ (A, B, S, Y); +input A, B, S; +output Y; +assign Y = S ? !B : !A; +endmodule + +// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| +//- //- $_MUX4_ (A, B, C, D, S, T, Y) //- //- A 4-input MUX gate. diff --git a/techlibs/common/simlib.v b/techlibs/common/simlib.v index a424d3089..7845a3fed 100644 --- a/techlibs/common/simlib.v +++ b/techlibs/common/simlib.v @@ -532,14 +532,26 @@ endmodule // -------------------------------------------------------- +// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| +//- +//- $lcu (P, G, CI, CO) +//- +//- Lookahead carry unit +//- A building block dedicated to fast computation of carry-bits used in binary +//- arithmetic operations. By replacing the ripple carry structure used in full-adder +//- blocks, the more significant bits of the sum can be expected to be computed more +//- quickly. +//- Typically created during `techmap` of $alu cells (see the "_90_alu" rule in +//- +/techmap.v). module \$lcu (P, G, CI, CO); parameter WIDTH = 1; -input [WIDTH-1:0] P, G; -input CI; +input [WIDTH-1:0] P; // Propagate +input [WIDTH-1:0] G; // Generate +input CI; // Carry-in -output reg [WIDTH-1:0] CO; +output reg [WIDTH-1:0] CO; // Carry-out integer i; always @* begin @@ -555,6 +567,17 @@ endmodule // -------------------------------------------------------- +// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| +//- +//- $alu (A, B, CI, BI, X, Y, CO) +//- +//- Arithmetic logic unit. +//- A building block supporting both binary addition/subtraction operations, and +//- indirectly, comparison operations. +//- Typically created by the `alumacc` pass, which transforms: +//- $add, $sub, $lt, $le, $ge, $gt, $eq, $eqx, $ne, $nex +//- cells into this $alu cell. +//- module \$alu (A, B, CI, BI, X, Y, CO); parameter A_SIGNED = 0; @@ -563,12 +586,16 @@ parameter A_WIDTH = 1; parameter B_WIDTH = 1; parameter Y_WIDTH = 1; -input [A_WIDTH-1:0] A; -input [B_WIDTH-1:0] B; -output [Y_WIDTH-1:0] X, Y; +input [A_WIDTH-1:0] A; // Input operand +input [B_WIDTH-1:0] B; // Input operand +output [Y_WIDTH-1:0] X; // A xor B (sign-extended, optional B inversion, + // used in combination with + // reduction-AND for $eq/$ne ops) +output [Y_WIDTH-1:0] Y; // Sum -input CI, BI; -output [Y_WIDTH-1:0] CO; +input CI; // Carry-in (set for $sub) +input BI; // Invert-B (set for $sub) +output [Y_WIDTH-1:0] CO; // Carry-out wire [Y_WIDTH-1:0] AA, BB; @@ -584,6 +611,7 @@ endgenerate wire y_co_undef = ^{A, A, B, B, CI, CI, BI, BI}; assign X = AA ^ BB; +// Full adder assign Y = (AA + BB + CI) ^ {Y_WIDTH{y_co_undef}}; function get_carry; diff --git a/techlibs/common/synth.cc b/techlibs/common/synth.cc index e41c0fe97..a176357a7 100644 --- a/techlibs/common/synth.cc +++ b/techlibs/common/synth.cc @@ -75,13 +75,16 @@ struct SynthPass : public ScriptPass log(" from label is synonymous to 'begin', and empty to label is\n"); log(" synonymous to the end of the command list.\n"); log("\n"); + log(" -abc9\n"); + log(" use new ABC9 flow (EXPERIMENTAL)\n"); + log("\n"); log("\n"); log("The following commands are executed by this synthesis command:\n"); help_script(); log("\n"); } - string top_module, fsm_opts, memory_opts; + string top_module, fsm_opts, memory_opts, abc; bool autotop, flatten, noalumacc, nofsm, noabc, noshare; int lut; @@ -98,6 +101,7 @@ struct SynthPass : public ScriptPass nofsm = false; noabc = false; noshare = false; + abc = "abc"; } void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE @@ -159,6 +163,10 @@ struct SynthPass : public ScriptPass noshare = true; continue; } + if (args[argidx] == "-abc9") { + abc = "abc9"; + continue; + } break; } extra_args(args, argidx, design); @@ -166,6 +174,9 @@ struct SynthPass : public ScriptPass if (!design->full_selection()) log_cmd_error("This command only operates on fully selected designs!\n"); + if (abc == "abc9" && !lut) + log_cmd_error("ABC9 flow only supported for FPGA synthesis (using '-lut' option)\n"); + log_header(design, "Executing SYNTH pass.\n"); log_push(); @@ -241,15 +252,15 @@ struct SynthPass : public ScriptPass #ifdef YOSYS_ENABLE_ABC if (help_mode) { - run("abc -fast", " (unless -noabc, unless -lut)"); - run("abc -fast -lut k", "(unless -noabc, if -lut)"); + run(abc + " -fast", " (unless -noabc, unless -lut)"); + run(abc + " -fast -lut k", "(unless -noabc, if -lut)"); } else { if (lut) - run(stringf("abc -fast -lut %d", lut)); + run(stringf("%s -fast -lut %d", abc.c_str(), lut)); else - run("abc -fast"); + run(abc + " -fast"); } run("opt -fast", " (unless -noabc)"); #endif |