From 603bee2b743f1a72222fd8586fa809555f08ea77 Mon Sep 17 00:00:00 2001 From: Nick McKinney Date: Thu, 8 Dec 2016 22:42:17 -0600 Subject: create super simple fetch stage --- fetch_stage.v | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 fetch_stage.v (limited to 'fetch_stage.v') diff --git a/fetch_stage.v b/fetch_stage.v new file mode 100644 index 0000000..03621c3 --- /dev/null +++ b/fetch_stage.v @@ -0,0 +1,34 @@ +module fetch_stage ( + input clk, + input en, + output reg ready, + + input [15:0] addr_in, + + output reg [15:0] instr_out +); + + always @(posedge clk) begin + if(en) begin + ready <= 1'b1; + + // sample proggy: + case(addr_in[15:1]) + 15'h0: instr_out <= 16'b0000_000_1_000_000_10; // xor r0,r0,r0 + 15'h1: instr_out <= 16'b0000_001_1_001_001_10; // xor r1,r1,r1 + 15'h2: instr_out <= 16'b0101_000_0_00010010; // mov rl0,$12 + 15'h3: instr_out <= 16'b0101_001_0_00110100; // mov rl1,$34 + 15'h4: instr_out <= 16'b0000_010_0_000_001_00; // add r2,r0,r1 + 15'h5: instr_out <= 16'b0000_011_0_001_000_01; // sub r3,r1,r0 + 15'h6: instr_out <= 16'b0100_000_0_011_00100; // mov r0,r3 + 15'h7: instr_out <= 16'b0000_100_1_100_100_10; // xor r4,r4,r4 + 15'h8: instr_out <= 16'b0111_00000_100_00000; // jmp r4 + default: instr_out <= 16'b1000_000000000000; // nop + endcase + end + else begin + ready <= 1'b0; + end + end + +endmodule -- cgit v1.2.3