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Diffstat (limited to 'techlibs/xilinx/lut_map.v')
| -rw-r--r-- | techlibs/xilinx/lut_map.v | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/techlibs/xilinx/lut_map.v b/techlibs/xilinx/lut_map.v new file mode 100644 index 000000000..13d3c3268 --- /dev/null +++ b/techlibs/xilinx/lut_map.v @@ -0,0 +1,119 @@ +/* + * 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. + * + */ + +// ============================================================================ +// LUT mapping + +`ifndef _NO_LUTS + +module \$lut (A, Y); + parameter WIDTH = 0; + parameter LUT = 0; + + input [WIDTH-1:0] A; + output Y; + + // Need to swap input ordering, and fix init accordingly, + // to match ABC's expectation of LUT inputs in non-decreasing + // delay order + function [WIDTH-1:0] permute_index; + input [WIDTH-1:0] i; + integer j; + begin + permute_index = 0; + for (j = 0; j < WIDTH; j = j + 1) + permute_index[WIDTH-1 - j] = i[j]; + end + endfunction + + function [2**WIDTH-1:0] permute_init; + input [2**WIDTH-1:0] orig; + integer i; + begin + permute_init = 0; + for (i = 0; i < 2**WIDTH; i = i + 1) + permute_init[i] = orig[permute_index(i)]; + end + endfunction + + parameter [2**WIDTH-1:0] P_LUT = permute_init(LUT); + + generate + if (WIDTH == 1) begin + LUT1 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[0])); + end else + if (WIDTH == 2) begin + LUT2 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[1]), .I1(A[0])); + end else + if (WIDTH == 3) begin + LUT3 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[2]), .I1(A[1]), .I2(A[0])); + end else + if (WIDTH == 4) begin + LUT4 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[3]), .I1(A[2]), .I2(A[1]), + .I3(A[0])); + end else + if (WIDTH == 5) begin + LUT5 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[4]), .I1(A[3]), .I2(A[2]), + .I3(A[1]), .I4(A[0])); + end else + if (WIDTH == 6) begin + LUT6 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[5]), .I1(A[4]), .I2(A[3]), + .I3(A[2]), .I4(A[1]), .I5(A[0])); + end else + if (WIDTH == 7) begin + wire T0, T1; + LUT6 #(.INIT(P_LUT[63:0])) fpga_lut_0 (.O(T0), + .I0(A[6]), .I1(A[5]), .I2(A[4]), + .I3(A[3]), .I4(A[2]), .I5(A[1])); + LUT6 #(.INIT(P_LUT[127:64])) fpga_lut_1 (.O(T1), + .I0(A[6]), .I1(A[5]), .I2(A[4]), + .I3(A[3]), .I4(A[2]), .I5(A[1])); + MUXF7 fpga_mux_0 (.O(Y), .I0(T0), .I1(T1), .S(A[0])); + end else + if (WIDTH == 8) begin + wire T0, T1, T2, T3, T4, T5; + LUT6 #(.INIT(P_LUT[63:0])) fpga_lut_0 (.O(T0), + .I0(A[7]), .I1(A[6]), .I2(A[5]), + .I3(A[4]), .I4(A[3]), .I5(A[2])); + LUT6 #(.INIT(P_LUT[127:64])) fpga_lut_1 (.O(T1), + .I0(A[7]), .I1(A[6]), .I2(A[5]), + .I3(A[4]), .I4(A[3]), .I5(A[2])); + LUT6 #(.INIT(P_LUT[191:128])) fpga_lut_2 (.O(T2), + .I0(A[7]), .I1(A[6]), .I2(A[5]), + .I3(A[4]), .I4(A[3]), .I5(A[2])); + LUT6 #(.INIT(P_LUT[255:192])) fpga_lut_3 (.O(T3), + .I0(A[7]), .I1(A[6]), .I2(A[5]), + .I3(A[4]), .I4(A[3]), .I5(A[2])); + MUXF7 fpga_mux_0 (.O(T4), .I0(T0), .I1(T1), .S(A[1])); + MUXF7 fpga_mux_1 (.O(T5), .I0(T2), .I1(T3), .S(A[1])); + MUXF8 fpga_mux_2 (.O(Y), .I0(T4), .I1(T5), .S(A[0])); + end else begin + wire _TECHMAP_FAIL_ = 1; + end + endgenerate +endmodule + +`endif + |