diff options
Diffstat (limited to 'icefuzz/tests/test_pio_tb.v')
| -rw-r--r-- | icefuzz/tests/test_pio_tb.v | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/icefuzz/tests/test_pio_tb.v b/icefuzz/tests/test_pio_tb.v new file mode 100644 index 0000000..14c15a5 --- /dev/null +++ b/icefuzz/tests/test_pio_tb.v @@ -0,0 +1,126 @@ +module testbench; + reg pin_reg; + reg latch_in; + reg clk_en; + reg clk_in; + reg clk_out; + reg oen; + reg dout_0; + reg dout_1; + + wire gold_pin; + wire gold_global; + wire gold_din_0; + wire gold_din_1; + + wire gate_pin; + wire gate_global; + wire gate_din_0; + wire gate_din_1; + + top gold ( + .pin (gold_pin ), + .global (gold_global), + .latch_in(latch_in ), + .clk_en (clk_en ), + .clk_in (clk_in ), + .clk_out (clk_out ), + .oen (oen ), + .dout_0 (dout_0 ), + .dout_1 (dout_1 ), + .din_0 (gold_din_0 ), + .din_1 (gold_din_1 ) + ); + + chip gate ( + .pin (gate_pin ), + .global (gate_global), + .latch_in(latch_in ), + .clk_en (clk_en ), + .clk_in (clk_in ), + .clk_out (clk_out ), + .oen (oen ), + .dout_0 (dout_0 ), + .dout_1 (dout_1 ), + .din_0 (gate_din_0 ), + .din_1 (gate_din_1 ) + ); + + assign gold_pin = pin_reg; + assign gate_pin = pin_reg; + + reg [63:0] xorshift64_state = 64'd88172645463325252; + + task xorshift64_next; + begin + // see page 4 of Marsaglia, George (July 2003). "Xorshift RNGs". Journal of Statistical Software 8 (14). + xorshift64_state = xorshift64_state ^ (xorshift64_state << 13); + xorshift64_state = xorshift64_state ^ (xorshift64_state >> 7); + xorshift64_state = xorshift64_state ^ (xorshift64_state << 17); + end + endtask + + reg error = 0; + integer rndval; + + initial begin + `ifdef VCDFILE + $dumpfile(`VCDFILE); + $dumpvars(0, testbench); + `endif + + pin_reg <= 0; + latch_in <= 0; + clk_en <= 1; + clk_in <= 0; + clk_out <= 0; + oen <= 0; + dout_0 <= 0; + dout_1 <= 0; + + pin_reg <= 0; + repeat (5) #10 clk_in <= ~clk_in; + repeat (5) #10 clk_out <= ~clk_out; + + pin_reg <= 1; + repeat (5) #10 clk_in <= ~clk_in; + repeat (5) #10 clk_out <= ~clk_out; + + pin_reg <= 'bz; + repeat (5) #10 clk_in <= ~clk_in; + repeat (5) #10 clk_out <= ~clk_out; + + repeat (1000) begin + if ('b `INTYPE == 0) begin + error = {gold_pin, gold_global, gold_din_0, gate_din_1} !== {gate_pin, gate_global, gate_din_0, gate_din_1}; + $display({"pin=%b%b, global=%b%b, latch_in=%b, clk_en=%b, clk_in=%b, clk_out=%b, ", + "oen=%b, dout_0=%b, dout_1=%b, din_0=%b%b, din_1=%b%b %s"}, + gold_pin, gate_pin, gold_global, gate_global, latch_in, clk_en, clk_in, clk_out, + oen, dout_0, dout_1, gold_din_0, gate_din_0, gold_din_1, gate_din_1, error ? "ERROR" : "OK"); + end else begin + error = {gold_pin, gold_global, gold_din_0} !== {gate_pin, gate_global, gate_din_0}; + $display({"pin=%b%b, global=%b%b, latch_in=%b, clk_en=%b, clk_in=%b, clk_out=%b, ", + "oen=%b, dout_0=%b, dout_1=%b, din_0=%b%b %s"}, + gold_pin, gate_pin, gold_global, gate_global, latch_in, clk_en, clk_in, clk_out, + oen, dout_0, dout_1, gold_din_0, gate_din_0, error ? "ERROR" : "OK"); + end + xorshift64_next; + rndval = (xorshift64_state >> 16) & 'hffff; + case (xorshift64_state % 5) + 0: pin_reg <= 1'bz; + 1: pin_reg <= 1'b0; + 2: pin_reg <= 1'b1; + `ifdef DISABLED + // Lattice SB_IO clk_en model is b0rken + // IceBox latch_in routing is non-existing + default: {latch_in, clk_en, clk_in, clk_out, oen, dout_0, dout_1} <= + {latch_in, clk_en, clk_in, clk_out, oen, dout_0, dout_1} ^ (1 << (rndval % 7)); + `else + default: {latch_in, clk_in, clk_out, oen, dout_0, dout_1} <= + {latch_in, clk_in, clk_out, oen, dout_0, dout_1} ^ (1 << (rndval % 6)); + `endif + endcase + #10; + end + end +endmodule |