From d4cad6096651774485723551336bce1d08402b6e Mon Sep 17 00:00:00 2001
From: Nick McKinney <nick@kmonkey.net>
Date: Sun, 18 Dec 2016 16:22:03 -0600
Subject: add simple control unit

---
 control_unit.v | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 control_unit.v

(limited to 'control_unit.v')

diff --git a/control_unit.v b/control_unit.v
new file mode 100644
index 0000000..00ebd4f
--- /dev/null
+++ b/control_unit.v
@@ -0,0 +1,36 @@
+module control_unit (
+	input clk,
+	
+	input fetch_ready,
+	
+	output fetch_en,
+	output decode_en,
+	output alu_en,
+	
+	output incr_pc,
+	
+	output [9:0] dbg_state
+);
+
+	reg [9:0] current_state;
+	
+	initial begin
+		current_state = 10'b1;
+	end
+	
+	assign fetch_en = current_state[0];
+	assign decode_en = current_state[1];
+	assign alu_en = current_state[2];
+	
+	assign incr_pc = current_state[1];
+	
+	always @(posedge clk) begin
+		case(current_state)
+			10'b1: if(fetch_ready) current_state <= 10'b10;
+			10'b10: current_state <= 10'b100;
+			10'b100: current_state <= 10'b1;
+		endcase
+	end
+	
+	assign dbg_state = current_state;
+endmodule
-- 
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