| module sequencer #( |
| // 01234567890123456789012345678901 |
| parameter [32*8-1:0] trace_a = "________________________________", |
| parameter [32*8-1:0] trace_b = "________________________________", |
| parameter [32*8-1:0] trace_c = "________________________________", |
| parameter [32*8-1:0] trace_d = "________________________________" |
| |
| ) ( |
| input clock, |
| output A, B, C, D |
| ); |
| integer t = 0; |
| always @(posedge clock) t <= t + (t < 31); |
| |
| assign A = trace_a[8*(31-t) +: 8] == "-"; |
| assign B = trace_b[8*(31-t) +: 8] == "-"; |
| assign C = trace_c[8*(31-t) +: 8] == "-"; |
| assign D = trace_d[8*(31-t) +: 8] == "-"; |
| endmodule |
| |
| module pass_00 (input clock); |
| wire A, B, C, D; |
| |
| sequencer #( |
| // 01234567890123456789012345678901 |
| .trace_a("_---____________________________"), |
| .trace_b("_----___________________________"), |
| .trace_c("_____-__________________________"), |
| .trace_d("________________________________") |
| ) uut (clock, A, B, C, D); |
| |
| assert property (@(posedge clock) (A [*3] and B [*4]) |=> C); |
| endmodule |
| |
| module fail_01 (input clock); |
| wire A, B, C, D; |
| |
| sequencer #( |
| // 01234567890123456789012345678901 |
| .trace_a("_---____________________________"), |
| .trace_b("_----___________________________"), |
| .trace_c("____-___________________________"), |
| .trace_d("________________________________") |
| ) uut (clock, A, B, C, D); |
| |
| assert property (@(posedge clock) (A [*3] and B [*4]) |=> C); |
| endmodule |
| |
| module fail_02 (input clock); |
| wire A, B, C, D; |
| |
| sequencer #( |
| // 01234567890123456789012345678901 |
| .trace_a("_---____________________________"), |
| .trace_b("_----___________________________"), |
| .trace_c("______-_________________________"), |
| .trace_d("________________________________") |
| ) uut (clock, A, B, C, D); |
| |
| assert property (@(posedge clock) (A [*3] and B [*4]) |=> C); |
| endmodule |