| // DESCRIPTION: Verilator: Verilog Test module |
| // |
| // This file ONLY is placed into the Public Domain, for any use, |
| // without warranty, 2011 by Jeremy Bennett. |
| |
| module t (/*AUTOARG*/ |
| // Inputs |
| clk |
| ); |
| input clk; |
| |
| wire [19:10] bitout; |
| wire [29:24] short_bitout; |
| wire [7:0] allbits; |
| wire [15:0] twobits; |
| |
| sub |
| i_sub1 [7:4] (.allbits (allbits), |
| .twobits (twobits[15:8]), |
| .bitout (bitout[17:14])), |
| i_sub2 [3:0] (.allbits (allbits), |
| .twobits (twobits[7:0]), |
| .bitout (bitout[13:10])); |
| |
| sub |
| i_sub3 [7:4] (.allbits (allbits), |
| .twobits (twobits[15:8]), |
| .bitout (bitout[17:14])); |
| |
| sub |
| i_sub4 [7:4] (.allbits (allbits), |
| .twobits (twobits[15:8]), |
| .bitout (short_bitout[27:24])); |
| |
| sub |
| i_sub5 [7:0] (.allbits (allbits), |
| .twobits (twobits), |
| .bitout (bitout[17:10])); |
| |
| sub |
| i_sub6 [7:4] (.allbits (allbits), |
| .twobits (twobits[15:8]), |
| .bitout ({bitout[18+:2],short_bitout[28+:2]})); |
| |
| integer cyc=0; |
| reg [63:0] crc; |
| reg [63:0] sum; |
| |
| // Signals under test |
| assign allbits = crc[7:0]; |
| assign twobits = crc[15:0]; |
| wire [63:0] result = {48'h0, short_bitout, bitout}; |
| |
| // Test loop |
| always @ (posedge clk) begin |
| `ifdef TEST_VERBOSE |
| $write("[%0t] cyc==%0d crc=%x result=%x\n",$time, cyc, crc, result); |
| `endif |
| cyc <= cyc + 1; |
| crc <= {crc[62:0], crc[63]^crc[2]^crc[0]}; |
| sum <= result ^ {sum[62:0],sum[63]^sum[2]^sum[0]}; |
| if (cyc==0) begin |
| // Setup |
| crc <= 64'h5aef0c8d_d70a4497; |
| sum <= 64'h0; |
| end |
| else if (cyc<10) begin |
| sum <= 64'h0; |
| end |
| else if (cyc<90) begin |
| end |
| else if (cyc==99) begin |
| $write("[%0t] cyc==%0d crc=%x sum=%x\n",$time, cyc, crc, sum); |
| if (crc !== 64'hc77bb9b3784ea091) $stop; |
| // What checksum will we end up with (above print should match) |
| `define EXPECTED_SUM 64'ha1da9ff8082a4ff6 |
| if (sum !== `EXPECTED_SUM) $stop; |
| $write("*-* All Finished *-*\n"); |
| $finish; |
| end |
| end |
| |
| endmodule // t |
| |
| |
| module sub |
| ( input wire [7:0] allbits, |
| input wire [1:0] twobits, |
| output wire bitout); |
| |
| assign bitout = (^ twobits) ^ (^ allbits); |
| |
| endmodule // sub |