Merge pull request #298 from yrabbit/ioregs-m

Implement FF in IO blocks.

examples/himbaechel/ioregs.v

@@ -0,0 +1,30 @@
+module top (
+	input clk,
+	input key_i,
+	input rst_i,
+	output [`LEDS_NR-1:0] led
+);
+
+wire key = key_i ^ `INV_BTN;
+wire reset = rst_i ^ `INV_BTN;
+
+reg [25:0] ctr_q;
+wire [25:0] ctr_d;
+
+always @(posedge clk) begin
+	if (reset) begin
+		ctr_q <= ctr_d;
+	end
+end
+
+reg [`LEDS_NR - 2:0] led_r;
+assign led = {ctr_q[25:25], led_r};
+assign ctr_d = ctr_q + 1'b1;
+
+always @(posedge clk) begin
+	if (!key) begin
+		led_r <= ctr_q[25:25-(`LEDS_NR - 2)];
+	end
+end
+
+endmodule