ifdef与c语言中的含义一样,这里你假设D3D_SYNC_RESET已定义那么代码将变成
always @(posedge clk_core) begin
if (rst_x == `D3D_RESET_POL) begin
r_state <= IDLE;
end else begin
case (r_state)
IDLE: begin
if (i_en) r_state <= LINE_0;
end
LINE_0: begin
if (i | w_reject_l0) r_state <= LINE_1;
end
LINE_1: begin
if (i | w_reject_l1) r_state <= LINE_2;
end
LINE_2: begin
if (i | w_reject_l2) r_state <= IDLE;
end
endcase
end
end