From 2be506209c28a82e10756bbf8c8a9fd0b3697688 Mon Sep 17 00:00:00 2001
From: Adam Magnusson <admag2001@gmail.com>
Date: Tue, 4 Mar 2025 16:33:49 +0100
Subject: [PATCH] Made instruction a byte instead of a bit

---
 src/control_unit.vhd    | 9 +++++----
 src/control_unit_tb.vhd | 8 ++++----
 src/io_type_pkg.vhd     | 6 ++++--
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/control_unit.vhd b/src/control_unit.vhd
index 64cbe0c..7c4095b 100644
--- a/src/control_unit.vhd
+++ b/src/control_unit.vhd
@@ -19,7 +19,8 @@ architecture behave of control_unit is
     address: std_logic_vector(address_width - 1 downto 0);
     seq_mem_access_count: std_logic_vector(seq_vector_length - 1 downto 0);
     curr_driver: std_logic_vector(number_of_drivers - 1 downto 0); --one-hot encoded, 0 means disabled
-    ready, is_write: std_logic;
+    ready: std_logic;
+    instruction: std_logic_vector(inst_word_width - 1 downto 0);
   end record state_t;
 
   signal state: state_t;
@@ -38,7 +39,7 @@ begin
     control_out.address <= state.address;
     control_out.seq_mem_access_count <= state.seq_mem_access_count;        
     control_out.ready <= state.ready;
-    control_out.is_write <= state.is_write;
+    control_out.instruction <= state.instruction;
   end process comb_proc;
 
   sync_proc: process(clk, state)
@@ -49,14 +50,14 @@ begin
                   (others => '0'), 
                   (others => '0'),
                   '1',
-                  '0');
+                  x"00");
       else
         state.ready <= not ored;
         if ored = '0' then
           state.address <= control_in.address;
           state.seq_mem_access_count <= control_in.seq_mem_access_count;
           state.curr_driver <= control_in.driver_id;
-          state.is_write <= control_in.is_write;
+          state.instruction <= control_in.instruction;
         end if;
       end if;
     end if;
diff --git a/src/control_unit_tb.vhd b/src/control_unit_tb.vhd
index 3921f52..62eefd8 100644
--- a/src/control_unit_tb.vhd
+++ b/src/control_unit_tb.vhd
@@ -18,13 +18,13 @@ architecture tb of control_unit_tb is
                                               (others => '0'),
                                               (others => '0'),
                                               (others => '0'),
-                                              '0');
+                                              x"00");
   signal control_output: control_unit_out_t := (
                                               (others => '0'),
                                               (others => '0'),
                                               (others => '1'),
                                               '1',
-                                              '0');
+                                              x"00");
   signal current_driver : std_logic_vector(2 downto 0) := "000";
   shared variable word_counter: natural := 0;
 
@@ -55,7 +55,7 @@ begin
   control_input.active_driver <= "000";
   control_input.address <= x"F0F0F0F0";
   control_input.seq_mem_access_count <= "00000011";
-  control_input.is_write <= '1';
+  control_input.instruction <= x"81";
   word_counter := 3;
   wait for cycle;
   current_driver <= "010";
@@ -79,7 +79,7 @@ begin
   wait for cycle;
   assert control_output.driver_id = "010" report "Incorrect driver_id from control_unit" severity error;
   assert control_output.address = x"F0F0F0F0" report "Incorrect address from control_unit" severity error;
-  assert control_output.is_write = '0' report "Incorrect memory op from control_unit" severity error;
+  assert control_output.instruction = x"81" report "Incorrect memory op from control_unit" severity error;
 
   wait for 5 * cycle;
   reset <= '1';
diff --git a/src/io_type_pkg.vhd b/src/io_type_pkg.vhd
index ea50409..6238419 100644
--- a/src/io_type_pkg.vhd
+++ b/src/io_type_pkg.vhd
@@ -18,19 +18,21 @@ package io_types is
   constant number_of_drivers: natural := 3;
   constant address_width: natural := 32;
   constant seq_vector_length: natural := 8;
+  constant inst_word_width: natural := 8;
 
   type control_unit_out_t is record
     driver_id: std_logic_vector(number_of_drivers - 1 downto 0);
     address: std_logic_vector(address_width - 1 downto 0);
     seq_mem_access_count: std_logic_vector(seq_vector_length - 1 downto 0);
-    ready, is_write: std_logic;
+    ready: std_logic;
+    instruction: std_logic_vector(inst_word_width - 1 downto 0);
   end record control_unit_out_t;
 
   type control_unit_in_t is record
     driver_id, active_driver: std_logic_vector(number_of_drivers - 1 downto 0);
     address: std_logic_vector(address_width - 1 downto 0);
     seq_mem_access_count: std_logic_vector(seq_vector_length - 1 downto 0);
-    is_write: std_logic;
+    instruction: std_logic_vector(inst_word_width - 1 downto 0);
   end record control_unit_in_t;
   --- PROTOCOL INFORMATION ---
   constant interface_inst : interface_inst_t := (