verilator/test_regress/t/t_cover_fsm_basic.v

57 lines
1.1 KiB
Systemverilog

// DESCRIPTION: Verilator: FSM coverage basic test
//
// This file ONLY is placed under the Creative Commons Public Domain.
// SPDX-FileCopyrightText: 2026 Wilson Snyder
// SPDX-License-Identifier: CC0-1.0
module t (
input clk
);
typedef enum logic [1:0] {
S_IDLE = 2'd0,
S_RUN = 2'd1,
S_DONE = 2'd2,
S_ERR = 2'd3
} state_t;
logic rst;
logic start;
integer cyc;
state_t state /*verilator fsm_reset_arc*/;
initial begin
rst = 1'b1;
start = 1'b0;
cyc = 0;
end
always @(posedge clk) begin
cyc <= cyc + 1;
if (cyc == 1) rst <= 1'b0;
if (cyc == 2) start <= 1'b1;
if (cyc == 3) start <= 1'b0;
if (cyc == 8) begin
$write("*-* All Finished *-*\n");
$finish;
end
end
always_ff @(posedge clk) begin
if (rst) begin
state <= S_IDLE;
end
else begin
case (state)
S_IDLE:
if (start) state <= S_RUN;
else state <= S_IDLE;
S_RUN: state <= S_DONE;
S_DONE: state <= S_DONE;
default: state <= S_ERR;
endcase
end
end
endmodule