OpenFPGA/yosys/techlibs/ice40/tests/test_ffs.v

43 lines
958 B
Verilog

module test(D, C, E, R, Q);
parameter [0:0] CLKPOL = 0;
parameter [0:0] ENABLE_EN = 0;
parameter [0:0] RESET_EN = 0;
parameter [0:0] RESET_VAL = 0;
parameter [0:0] RESET_SYN = 0;
(* gentb_clock *)
input D, C, E, R;
output Q;
wire gated_reset = R & RESET_EN;
wire gated_enable = E | ~ENABLE_EN;
reg posedge_q, negedge_q, posedge_sq, negedge_sq;
always @(posedge C, posedge gated_reset)
if (gated_reset)
posedge_q <= RESET_VAL;
else if (gated_enable)
posedge_q <= D;
always @(negedge C, posedge gated_reset)
if (gated_reset)
negedge_q <= RESET_VAL;
else if (gated_enable)
negedge_q <= D;
always @(posedge C)
if (gated_reset)
posedge_sq <= RESET_VAL;
else if (gated_enable)
posedge_sq <= D;
always @(negedge C)
if (gated_reset)
negedge_sq <= RESET_VAL;
else if (gated_enable)
negedge_sq <= D;
assign Q = RESET_SYN ? (CLKPOL ? posedge_sq : negedge_sq) : (CLKPOL ? posedge_q : negedge_q);
endmodule