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| 1 | +(* techmap_celltype = "$alu" *) |
| 2 | +module _80_quicklogic_alu (A, B, CI, BI, X, Y, CO); |
| 3 | + parameter A_SIGNED = 0; |
| 4 | + parameter B_SIGNED = 0; |
| 5 | + parameter A_WIDTH = 1; |
| 6 | + parameter B_WIDTH = 1; |
| 7 | + parameter Y_WIDTH = 1; |
| 8 | + |
| 9 | + parameter _TECHMAP_CONSTMSK_CI_ = 0; |
| 10 | + parameter _TECHMAP_CONSTVAL_CI_ = 0; |
| 11 | + |
| 12 | + (* force_downto *) |
| 13 | + input [A_WIDTH-1:0] A; |
| 14 | + (* force_downto *) |
| 15 | + input [B_WIDTH-1:0] B; |
| 16 | + (* force_downto *) |
| 17 | + output [Y_WIDTH-1:0] X, Y; |
| 18 | + |
| 19 | + input CI, BI; |
| 20 | + (* force_downto *) |
| 21 | + output [Y_WIDTH-1:0] CO; |
| 22 | + |
| 23 | + wire _TECHMAP_FAIL_ = Y_WIDTH <= 2; |
| 24 | + |
| 25 | + (* force_downto *) |
| 26 | + wire [Y_WIDTH-1:0] A_buf, B_buf; |
| 27 | + \$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf)); |
| 28 | + \$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf)); |
| 29 | + |
| 30 | + (* force_downto *) |
| 31 | + wire [Y_WIDTH-1:0] AA = A_buf; |
| 32 | + (* force_downto *) |
| 33 | + wire [Y_WIDTH-1:0] BB = BI ? ~B_buf : B_buf; |
| 34 | + (* force_downto *) |
| 35 | + wire [Y_WIDTH-1:0] C; |
| 36 | + |
| 37 | + assign CO = C[Y_WIDTH-1]; |
| 38 | + |
| 39 | + genvar i; |
| 40 | + generate for (i = 0; i < Y_WIDTH; i = i + 1) begin: slice |
| 41 | + |
| 42 | + wire ci; |
| 43 | + wire co; |
| 44 | + |
| 45 | + // First in chain |
| 46 | + generate if (i == 0) begin |
| 47 | + |
| 48 | + // CI connected to a constant |
| 49 | + if (_TECHMAP_CONSTMSK_CI_ == 1) begin |
| 50 | + |
| 51 | + localparam INIT = (_TECHMAP_CONSTVAL_CI_ == 0) ? |
| 52 | + 16'b0110_0000_0000_0001 : |
| 53 | + 16'b1001_0000_0000_0111; |
| 54 | + |
| 55 | + // LUT4 configured as 1-bit adder with CI=const |
| 56 | + adder_lut4 #( |
| 57 | + .LUT(INIT), |
| 58 | + .IN2_IS_CIN(1'b0) |
| 59 | + ) lut_ci_adder ( |
| 60 | + .in({AA[i], BB[i], 1'b0, 1'b0}), |
| 61 | + .cin(), |
| 62 | + .lut4_out(Y[i]), |
| 63 | + .cout(ci) |
| 64 | + ); |
| 65 | + |
| 66 | + // CI connected to a non-const driver |
| 67 | + end else begin |
| 68 | + |
| 69 | + // LUT4 configured as passthrough to drive CI of the next stage |
| 70 | + adder_lut4 #( |
| 71 | + .LUT(16'b1100_0000_0000_0011), |
| 72 | + .IN2_IS_CIN(1'b0) |
| 73 | + ) lut_ci ( |
| 74 | + .in({1'b0,CI,1'b0,1'b0}), |
| 75 | + .cin(), |
| 76 | + .lut4_out(), |
| 77 | + .cout(ci) |
| 78 | + ); |
| 79 | + end |
| 80 | + |
| 81 | + // Not first in chain |
| 82 | + end else begin |
| 83 | + assign ci = C[i-1]; |
| 84 | + |
| 85 | + end endgenerate |
| 86 | + |
| 87 | + // .................................................... |
| 88 | + |
| 89 | + // Single 1-bit adder, mid-chain adder or non-const CI |
| 90 | + // adder |
| 91 | + generate if ((i == 0 && _TECHMAP_CONSTMSK_CI_ == 0) || (i > 0)) begin |
| 92 | + |
| 93 | + // LUT4 configured as full 1-bit adder |
| 94 | + adder_lut4 #( |
| 95 | + .LUT(16'b0110_1001_0110_0001), |
| 96 | + .IN2_IS_CIN(1'b1) |
| 97 | + ) lut_adder ( |
| 98 | + .in({AA[i], BB[i], 1'b0, 1'b0}), |
| 99 | + .cin(ci), |
| 100 | + .lut4_out(Y[i]), |
| 101 | + .cout(co) |
| 102 | + ); |
| 103 | + end else begin |
| 104 | + assign co = ci; |
| 105 | + |
| 106 | + end endgenerate |
| 107 | + |
| 108 | + // .................................................... |
| 109 | + |
| 110 | + // Last in chain |
| 111 | + generate if (i == Y_WIDTH-1) begin |
| 112 | + |
| 113 | + // LUT4 configured for passing its CI input to output. This should |
| 114 | + // get pruned if the actual CO port is not connected anywhere. |
| 115 | + adder_lut4 #( |
| 116 | + .LUT(16'b0000_1111_0000_1111), |
| 117 | + .IN2_IS_CIN(1'b1) |
| 118 | + ) lut_co ( |
| 119 | + .in({1'b0, co, 1'b0, 1'b0}), |
| 120 | + .cin(co), |
| 121 | + .lut4_out(C[i]), |
| 122 | + .cout() |
| 123 | + ); |
| 124 | + // Not last in chain |
| 125 | + end else begin |
| 126 | + assign C[i] = co; |
| 127 | + |
| 128 | + end endgenerate |
| 129 | + |
| 130 | + end: slice |
| 131 | + endgenerate |
| 132 | + |
| 133 | + /* End implementation */ |
| 134 | + assign X = AA ^ BB; |
| 135 | +endmodule |
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