From 9ff05a96e5a31df902293c90af2fec2531d8ee36 Mon Sep 17 00:00:00 2001
From: Wojciech Kosior <kwojtus@protonmail.com>
Date: Wed, 2 Sep 2020 09:10:01 +0200
Subject: add tee instruction

---
 design/stack_machine.v | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'design')

diff --git a/design/stack_machine.v b/design/stack_machine.v
index 1fddb18..d466cc8 100644
--- a/design/stack_machine.v
+++ b/design/stack_machine.v
@@ -127,6 +127,7 @@ module stack_machine
    assign extended_instruction_bits = instruction[8:0];
 
    /* extended instructions */
+   parameter INSTR_TEE = 9'd7;
    parameter INSTR_MUL = 9'd6;
    parameter INSTR_DIV = 9'd5;
    parameter INSTR_SUB = 9'd4;
@@ -326,6 +327,8 @@ module stack_machine
 		   end
 		   INSTR_MUL :
 		     r0 <= r0 * r1;
+		   INSTR_TEE :
+		     r1 <= r0;
 		   default : begin
 `ifdef SIMULATION
 		      $display("operation not implemented yet");
-- 
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