After the 9-bit counter ref_timer in the first always block in the program counts to 0, it returns to 511, and when it is called again, it decrements from the set count value. The ref_timer value in the second block will remain at the lowest value after the first decrement ends, and will decrement from the set count value when it is called again. I want to know the difference, thanks for the answer!
module ref_timer(
input clk,
input rst_n,
input INIT_REQ,
output REF_REQ1,
output REF_REQ2
);
// reg define
reg ref_req1;
reg ref_req2;
reg [8:0] ref_timer;
reg [8:0] ref_timer2;
always@(posedge clk or negedge rst_n)begin
IF(!rst_n)begin
ref_timer <= 0;
ref_req1 <= 0;
end
else begin
if(INIT_REQ == 1) begin
ref_timer <= 9'd50;
ref_req1 <=0;
end
else
ref_timer <= ref_timer - 1'd1;
if (ref_timer == 1)
ref_req1 <= 1;
end
end
always@(posedge clk or negedge rst_n)begin
if(!rst_n)begin
ref_timer2 <= 0;
ref_req2 <= 0;
end
else begin
if(INIT_REQ == 1) begin
ref_timer2 <= 9'd50;
ref_req2 <=0;
end
else if(ref_timer2 == 1)
ref_req2 = 1'd1;
else
ref_timer2 <= ref_timer2 - 1'd1;
end
end
// assign define
assign REF_REQ1 = ref_req1;
assign REF_REQ2 = ref_req2;
endmodule
