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authorMarcin Koƛcielnicki <mwk@0x04.net>2020-02-03 16:19:24 +0100
committerMarcelina Koƛcielnicka <mwk@0x04.net>2020-02-07 09:03:22 +0100
commitd48950d92d748cc24ecfefc5beab19ea899982df (patch)
treee6afcdf7cc679215b88b996752da26de6c913729 /techlibs
parent1f54b0008f6fe4e9ed19f5b4fcddddcb4d6d8976 (diff)
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xilinx: Initial support for LUT4 devices.
Adds support for mapping logic, including LUTs, wide LUTs, and carry chains. Fixes #1547
Diffstat (limited to 'techlibs')
-rw-r--r--techlibs/xilinx/arith_map.v53
-rw-r--r--techlibs/xilinx/lut_map.v54
-rw-r--r--techlibs/xilinx/synth_xilinx.cc98
3 files changed, 152 insertions, 53 deletions
diff --git a/techlibs/xilinx/arith_map.v b/techlibs/xilinx/arith_map.v
index 4ae938827..2b8b0dcc1 100644
--- a/techlibs/xilinx/arith_map.v
+++ b/techlibs/xilinx/arith_map.v
@@ -34,6 +34,12 @@ module _80_xilinx_lcu (P, G, CI, CO);
genvar i;
`ifdef _EXPLICIT_CARRY
+ localparam EXPLICIT_CARRY = 1'b1;
+`else
+ localparam EXPLICIT_CARRY = 1'b0;
+`endif
+
+generate if (EXPLICIT_CARRY || `LUT_SIZE == 4) begin
wire [WIDTH-1:0] C = {CO, CI};
wire [WIDTH-1:0] S = P & ~G;
@@ -47,7 +53,7 @@ module _80_xilinx_lcu (P, G, CI, CO);
);
end endgenerate
-`else
+end else begin
localparam CARRY4_COUNT = (WIDTH + 3) / 4;
localparam MAX_WIDTH = CARRY4_COUNT * 4;
@@ -79,7 +85,7 @@ module _80_xilinx_lcu (P, G, CI, CO);
);
end
end endgenerate
-`endif
+end endgenerate
endmodule
@@ -116,9 +122,34 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
genvar i;
`ifdef _EXPLICIT_CARRY
+ localparam EXPLICIT_CARRY = 1'b1;
+`else
+ localparam EXPLICIT_CARRY = 1'b0;
+`endif
+
+generate if (`LUT_SIZE == 4) begin
+
+ wire [Y_WIDTH-1:0] C = {CO, CI};
+ wire [Y_WIDTH-1:0] S = {AA ^ BB};
+
+ genvar i;
+ generate for (i = 0; i < Y_WIDTH; i = i + 1) begin:slice
+ MUXCY muxcy (
+ .CI(C[i]),
+ .DI(AA[i]),
+ .S(S[i]),
+ .O(CO[i])
+ );
+ XORCY xorcy (
+ .CI(C[i]),
+ .LI(S[i]),
+ .O(Y[i])
+ );
+ end endgenerate
+
+end else if (EXPLICIT_CARRY) begin
wire [Y_WIDTH-1:0] S = AA ^ BB;
- wire [Y_WIDTH-1:0] DI = AA & BB;
wire CINIT;
// Carry chain.
@@ -138,7 +169,7 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
generate for (i = 0; i < 1; i = i + 1) begin:slice
CARRY0 #(.CYINIT_FABRIC(1)) carry(
.CI_INIT(CI),
- .DI(DI[0]),
+ .DI(AA[0]),
.S(S[0]),
.CO_CHAIN(CO_CHAIN[0]),
.CO_FABRIC(CO[0]),
@@ -150,7 +181,7 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
if(i % 4 == 0) begin
CARRY0 carry (
.CI(C[i]),
- .DI(DI[i]),
+ .DI(AA[i]),
.S(S[i]),
.CO_CHAIN(CO_CHAIN[i]),
.CO_FABRIC(CO[i]),
@@ -161,7 +192,7 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
begin
CARRY carry (
.CI(C[i]),
- .DI(DI[i]),
+ .DI(AA[i]),
.S(S[i]),
.CO_CHAIN(CO_CHAIN[i]),
.CO_FABRIC(CO[i]),
@@ -174,7 +205,7 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
if(i % 4 == 0) begin
CARRY0 top_of_carry (
.CI(C[i]),
- .DI(DI[i]),
+ .DI(AA[i]),
.S(S[i]),
.CO_CHAIN(CO_CHAIN[i]),
.O(Y[i])
@@ -184,7 +215,7 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
begin
CARRY top_of_carry (
.CI(C[i]),
- .DI(DI[i]),
+ .DI(AA[i]),
.S(S[i]),
.CO_CHAIN(CO_CHAIN[i]),
.O(Y[i])
@@ -213,14 +244,14 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
end
end endgenerate
-`else
+end else begin
localparam CARRY4_COUNT = (Y_WIDTH + 3) / 4;
localparam MAX_WIDTH = CARRY4_COUNT * 4;
localparam PAD_WIDTH = MAX_WIDTH - Y_WIDTH;
wire [MAX_WIDTH-1:0] S = {{PAD_WIDTH{1'b0}}, AA ^ BB};
- wire [MAX_WIDTH-1:0] DI = {{PAD_WIDTH{1'b0}}, AA & BB};
+ wire [MAX_WIDTH-1:0] DI = {{PAD_WIDTH{1'b0}}, AA};
wire [MAX_WIDTH-1:0] O;
wire [MAX_WIDTH-1:0] C;
@@ -251,7 +282,7 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
end
end endgenerate
-`endif
+end endgenerate
assign X = S;
endmodule
diff --git a/techlibs/xilinx/lut_map.v b/techlibs/xilinx/lut_map.v
index 718ec42f1..ec2e3b234 100644
--- a/techlibs/xilinx/lut_map.v
+++ b/techlibs/xilinx/lut_map.v
@@ -51,43 +51,45 @@ module \$lut (A, Y);
.I0(A[0]), .I1(A[1]), .I2(A[2]),
.I3(A[3]));
end else
- if (WIDTH == 5) begin
+ if (WIDTH == 5 && WIDTH <= `LUT_WIDTH) begin
LUT5 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
.I0(A[0]), .I1(A[1]), .I2(A[2]),
.I3(A[3]), .I4(A[4]));
end else
- if (WIDTH == 6) begin
+ if (WIDTH == 6 && WIDTH <= `LUT_WIDTH) begin
LUT6 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
.I0(A[0]), .I1(A[1]), .I2(A[2]),
.I3(A[3]), .I4(A[4]), .I5(A[5]));
end else
+ if (WIDTH == 5 && WIDTH > `LUT_WIDTH) begin
+ wire f0, f1;
+ \$lut #(.LUT(LUT[15: 0]), .WIDTH(4)) lut0 (.A(A[3:0]), .Y(f0));
+ \$lut #(.LUT(LUT[31:16]), .WIDTH(4)) lut1 (.A(A[3:0]), .Y(f1));
+ MUXF5 mux5(.I0(f0), .I1(f1), .S(A[4]), .O(Y));
+ end else
+ if (WIDTH == 6 && WIDTH > `LUT_WIDTH) begin
+ wire f0, f1;
+ \$lut #(.LUT(LUT[31: 0]), .WIDTH(5)) lut0 (.A(A[4:0]), .Y(f0));
+ \$lut #(.LUT(LUT[63:32]), .WIDTH(5)) lut1 (.A(A[4:0]), .Y(f1));
+ MUXF6 mux6(.I0(f0), .I1(f1), .S(A[5]), .O(Y));
+ end else
if (WIDTH == 7) begin
- wire T0, T1;
- LUT6 #(.INIT(LUT[63:0])) fpga_lut_0 (.O(T0),
- .I0(A[0]), .I1(A[1]), .I2(A[2]),
- .I3(A[3]), .I4(A[4]), .I5(A[5]));
- LUT6 #(.INIT(LUT[127:64])) fpga_lut_1 (.O(T1),
- .I0(A[0]), .I1(A[1]), .I2(A[2]),
- .I3(A[3]), .I4(A[4]), .I5(A[5]));
- MUXF7 fpga_mux_0 (.O(Y), .I0(T0), .I1(T1), .S(A[6]));
+ wire f0, f1;
+ \$lut #(.LUT(LUT[ 63: 0]), .WIDTH(6)) lut0 (.A(A[5:0]), .Y(f0));
+ \$lut #(.LUT(LUT[127:64]), .WIDTH(6)) lut1 (.A(A[5:0]), .Y(f1));
+ MUXF7 mux7(.I0(f0), .I1(f1), .S(A[6]), .O(Y));
end else
if (WIDTH == 8) begin
- wire T0, T1, T2, T3, T4, T5;
- LUT6 #(.INIT(LUT[63:0])) fpga_lut_0 (.O(T0),
- .I0(A[0]), .I1(A[1]), .I2(A[2]),
- .I3(A[3]), .I4(A[4]), .I5(A[5]));
- LUT6 #(.INIT(LUT[127:64])) fpga_lut_1 (.O(T1),
- .I0(A[0]), .I1(A[1]), .I2(A[2]),
- .I3(A[3]), .I4(A[4]), .I5(A[5]));
- LUT6 #(.INIT(LUT[191:128])) fpga_lut_2 (.O(T2),
- .I0(A[0]), .I1(A[1]), .I2(A[2]),
- .I3(A[3]), .I4(A[4]), .I5(A[5]));
- LUT6 #(.INIT(LUT[255:192])) fpga_lut_3 (.O(T3),
- .I0(A[0]), .I1(A[1]), .I2(A[2]),
- .I3(A[3]), .I4(A[4]), .I5(A[5]));
- MUXF7 fpga_mux_0 (.O(T4), .I0(T0), .I1(T1), .S(A[6]));
- MUXF7 fpga_mux_1 (.O(T5), .I0(T2), .I1(T3), .S(A[6]));
- MUXF8 fpga_mux_2 (.O(Y), .I0(T4), .I1(T5), .S(A[7]));
+ wire f0, f1;
+ \$lut #(.LUT(LUT[127: 0]), .WIDTH(7)) lut0 (.A(A[6:0]), .Y(f0));
+ \$lut #(.LUT(LUT[255:128]), .WIDTH(7)) lut1 (.A(A[6:0]), .Y(f1));
+ MUXF8 mux8(.I0(f0), .I1(f1), .S(A[7]), .O(Y));
+ end else
+ if (WIDTH == 9) begin
+ wire f0, f1;
+ \$lut #(.LUT(LUT[255: 0]), .WIDTH(8)) lut0 (.A(A[7:0]), .Y(f0));
+ \$lut #(.LUT(LUT[511:256]), .WIDTH(8)) lut1 (.A(A[7:0]), .Y(f1));
+ MUXF9 mux9(.I0(f0), .I1(f1), .S(A[8]), .O(Y));
end else begin
wire _TECHMAP_FAIL_ = 1;
end
diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc
index a7fa73837..fe58eb6d3 100644
--- a/techlibs/xilinx/synth_xilinx.cc
+++ b/techlibs/xilinx/synth_xilinx.cc
@@ -49,10 +49,25 @@ struct SynthXilinxPass : public ScriptPass
log(" -top <module>\n");
log(" use the specified module as top module\n");
log("\n");
- log(" -family {xcup|xcu|xc7|xc6v|xc5v|xc6s}\n");
+ log(" -family <family>\n");
log(" run synthesis for the specified Xilinx architecture\n");
log(" generate the synthesis netlist for the specified family.\n");
- log(" default: xc7\n");
+ log(" supported values:\n");
+ log(" - xcup: Ultrascale Plus\n");
+ log(" - xcu: Ultrascale\n");
+ log(" - xc7: Series 7 (default)\n");
+ log(" - xc6s: Spartan 6\n");
+ log(" - xc6v: Virtex 6\n");
+ log(" - xc5v: Virtex 5 (EXPERIMENTAL)\n");
+ log(" - xc4v: Virtex 4 (EXPERIMENTAL)\n");
+ log(" - xc3sda: Spartan 3A DSP (EXPERIMENTAL)\n");
+ log(" - xc3sa: Spartan 3A (EXPERIMENTAL)\n");
+ log(" - xc3se: Spartan 3E (EXPERIMENTAL)\n");
+ log(" - xc3s: Spartan 3 (EXPERIMENTAL)\n");
+ log(" - xc2vp: Virtex 2 Pro (EXPERIMENTAL)\n");
+ log(" - xc2v: Virtex 2 (EXPERIMENTAL)\n");
+ log(" - xcve: Virtex E, Spartan 2E (EXPERIMENTAL)\n");
+ log(" - xcv: Virtex, Spartan 2 (EXPERIMENTAL)\n");
log("\n");
log(" -edif <file>\n");
log(" write the design to the specified edif file. writing of an output file\n");
@@ -82,10 +97,10 @@ struct SynthXilinxPass : public ScriptPass
log(" do not use XORCY/MUXCY/CARRY4 cells in output netlist\n");
log("\n");
log(" -nowidelut\n");
- log(" do not use MUXF[78] resources to implement LUTs larger than LUT6s\n");
+ log(" do not use MUXF[5-9] resources to implement LUTs larger than native for the target\n");
log("\n");
log(" -nodsp\n");
- log(" do not use DSP48E1s to implement multipliers and associated logic\n");
+ log(" do not use DSP48*s to implement multipliers and associated logic\n");
log("\n");
log(" -noiopad\n");
log(" disable I/O buffer insertion (useful for hierarchical or \n");
@@ -131,6 +146,8 @@ struct SynthXilinxPass : public ScriptPass
bool abc9, dff_mode;
bool flatten_before_abc;
int widemux;
+ int lut_size;
+ int widelut_size;
void clear_flags() YS_OVERRIDE
{
@@ -156,6 +173,7 @@ struct SynthXilinxPass : public ScriptPass
dff_mode = false;
flatten_before_abc = false;
widemux = 0;
+ lut_size = 6;
}
void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
@@ -270,9 +288,39 @@ struct SynthXilinxPass : public ScriptPass
}
extra_args(args, argidx, design);
- if (family != "xcup" && family != "xcu" && family != "xc7" && family != "xc6v" && family != "xc5v" && family != "xc6s")
+ if (family == "xcup" || family == "xcu") {
+ lut_size = 6;
+ widelut_size = 9;
+ } else if (family == "xc7" ||
+ family == "xc6v" ||
+ family == "xc5v" ||
+ family == "xc6s") {
+ lut_size = 6;
+ widelut_size = 8;
+ } else if (family == "xc4v" ||
+ family == "xc3sda" ||
+ family == "xc3sa" ||
+ family == "xc3se" ||
+ family == "xc3s" ||
+ family == "xc2vp" ||
+ family == "xc2v") {
+ lut_size = 4;
+ widelut_size = 8;
+ } else if (family == "xcve" || family == "xcv") {
+ lut_size = 4;
+ widelut_size = 6;
+ } else
log_cmd_error("Invalid Xilinx -family setting: '%s'.\n", family.c_str());
+ if (widemux != 0 && lut_size != 6)
+ log_cmd_error("-widemux is not currently supported for LUT4-based architectures.\n");
+
+ if (lut_size != 6) {
+ log_warning("Shift register inference not yet supported for family %s.\n", family.c_str());
+ nosrl = true;
+ nolutram = true;
+ }
+
if (widemux != 0 && widemux < 2)
log_cmd_error("-widemux value must be 0 or >= 2.\n");
@@ -292,6 +340,9 @@ struct SynthXilinxPass : public ScriptPass
void script() YS_OVERRIDE
{
+ std::string lut_size_s = std::to_string(lut_size);
+ if (help_mode)
+ lut_size_s = "[46]";
std::string ff_map_file;
if (help_mode)
ff_map_file = "+/xilinx/{family}_ff_map.v";
@@ -344,7 +395,7 @@ struct SynthXilinxPass : public ScriptPass
run("clean", " (skip if '-nosrl' and '-widemux=0')");
}
- run("techmap -map +/cmp2lut.v -D LUT_WIDTH=6");
+ run("techmap -map +/cmp2lut.v -D LUT_WIDTH=" + lut_size_s);
}
if (check_label("map_dsp", "(skip if '-nodsp')")) {
@@ -353,7 +404,7 @@ struct SynthXilinxPass : public ScriptPass
// NB: Xilinx multipliers are signed only
if (help_mode)
run("techmap -map +/mul2dsp.v -map +/xilinx/{family}_dsp_map.v {options}");
- else if (family == "xc2v" || family == "xc3s" || family == "xc3se" || family == "xc3sa")
+ else if (family == "xc2v" || family == "xc2vp" || family == "xc3s" || family == "xc3se" || family == "xc3sa")
run("techmap -map +/mul2dsp.v -map +/xilinx/xc3s_mult_map.v -D DSP_A_MAXWIDTH=18 -D DSP_B_MAXWIDTH=18 "
"-D DSP_A_MINWIDTH=2 -D DSP_B_MINWIDTH=2 " // Blocks Nx1 multipliers
"-D DSP_Y_MINWIDTH=9 " // UG901 suggests small multiplies are those 4x4 and smaller
@@ -523,14 +574,12 @@ struct SynthXilinxPass : public ScriptPass
if (!nosrl || help_mode)
run("xilinx_srl -variable -minlen 3", "(skip if '-nosrl')");
- std::string techmap_args = " -map +/techmap.v";
+ std::string techmap_args = " -map +/techmap.v -D LUT_SIZE=" + lut_size_s;
if (help_mode)
techmap_args += " [-map +/xilinx/mux_map.v]";
else if (widemux > 0)
techmap_args += stringf(" -D MIN_MUX_INPUTS=%d -map +/xilinx/mux_map.v", widemux);
- if (help_mode)
- techmap_args += " [-map +/xilinx/arith_map.v]";
- else if (!nocarry) {
+ if (!nocarry) {
techmap_args += " -map +/xilinx/arith_map.v";
if (vpr)
techmap_args += " -D _EXPLICIT_CARRY";
@@ -563,6 +612,8 @@ struct SynthXilinxPass : public ScriptPass
if (help_mode)
run("abc -luts 2:2,3,6:5[,10,20] [-dff] [-D 1]", "(option for 'nowidelut', '-dff', '-retime')");
else if (abc9) {
+ if (lut_size != 6)
+ log_error("'synth_xilinx -abc9' not currently supported for LUT4-based devices.\n");
if (family != "xc7")
log_warning("'synth_xilinx -abc9' not currently supported for the '%s' family, "
"will use timing for 'xc7' instead.\n", family.c_str());
@@ -588,10 +639,19 @@ struct SynthXilinxPass : public ScriptPass
}
else {
std::string abc_opts;
- if (nowidelut)
- abc_opts += " -luts 2:2,3,6:5";
- else
- abc_opts += " -luts 2:2,3,6:5,10,20";
+ if (lut_size != 6) {
+ if (nowidelut)
+ abc_opts += " -lut " + lut_size_s;
+ else
+ abc_opts += " -lut " + lut_size_s + ":" + std::to_string(widelut_size);
+ } else {
+ if (nowidelut)
+ abc_opts += " -luts 2:2,3,6:5";
+ else if (widelut_size == 8)
+ abc_opts += " -luts 2:2,3,6:5,10,20";
+ else
+ abc_opts += " -luts 2:2,3,6:5,10,20,40";
+ }
if (dff_mode)
abc_opts += " -dff";
if (retime)
@@ -607,8 +667,14 @@ struct SynthXilinxPass : public ScriptPass
std::string techmap_args = "-map +/xilinx/lut_map.v -map +/xilinx/cells_map.v";
if (help_mode || !abc9)
techmap_args += stringf(" -map %s", ff_map_file.c_str());
+ techmap_args += " -D LUT_WIDTH=" + lut_size_s;
run("techmap " + techmap_args);
- run("xilinx_dffopt");
+ if (help_mode)
+ run("xilinx_dffopt [-lut4]");
+ else if (lut_size == 4)
+ run("xilinx_dffopt -lut4");
+ else
+ run("xilinx_dffopt");
run("opt_lut_ins -tech xilinx");
}