From 7a24dc8febbb4702ea0cdb3fb912325d8529de96 Mon Sep 17 00:00:00 2001
From: Adam Magnusson <admag2001@gmail.com>
Date: Tue, 4 Mar 2025 14:54:15 +0100
Subject: [PATCH] Control unit tested and seems to work for the requirements of
 the basic version

---
 src/control_unit.vhd    |  7 +++++--
 src/control_unit_tb.vhd | 15 +++++++++++----
 src/io_type_pkg.vhd     |  3 ++-
 3 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/control_unit.vhd b/src/control_unit.vhd
index 6c67401..64cbe0c 100644
--- a/src/control_unit.vhd
+++ b/src/control_unit.vhd
@@ -19,7 +19,7 @@ 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: std_logic;
+    ready, is_write: std_logic;
   end record state_t;
 
   signal state: state_t;
@@ -38,6 +38,7 @@ 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;
   end process comb_proc;
 
   sync_proc: process(clk, state)
@@ -47,13 +48,15 @@ begin
         state <= ((others => '0'), 
                   (others => '0'), 
                   (others => '0'),
-                  '1');
+                  '1',
+                  '0');
       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;
         end if;
       end if;
     end if;
diff --git a/src/control_unit_tb.vhd b/src/control_unit_tb.vhd
index 0f2ce51..3921f52 100644
--- a/src/control_unit_tb.vhd
+++ b/src/control_unit_tb.vhd
@@ -17,12 +17,14 @@ architecture tb of control_unit_tb is
                                               (others => '0'),
                                               (others => '0'),
                                               (others => '0'),
-                                              "00000011");
+                                              (others => '0'),
+                                              '0');
   signal control_output: control_unit_out_t := (
                                               (others => '0'),
                                               (others => '0'),
                                               (others => '1'),
-                                              '1');
+                                              '1',
+                                              '0');
   signal current_driver : std_logic_vector(2 downto 0) := "000";
   shared variable word_counter: natural := 0;
 
@@ -52,7 +54,8 @@ begin
   control_input.driver_id <= "010";
   control_input.active_driver <= "000";
   control_input.address <= x"F0F0F0F0";
-  control_input.seq_mem_access_count <= "00000111";
+  control_input.seq_mem_access_count <= "00000011";
+  control_input.is_write <= '1';
   word_counter := 3;
   wait for cycle;
   current_driver <= "010";
@@ -60,7 +63,7 @@ begin
   report "entering loop with word_counter" & integer'image(word_counter);
   for_loop: for i in word_counter - 1 downto 0 loop
     wait for cycle;
-    report "word counter is " & integer'image(word_counter);
+    report "words remaining are " & integer'image(i);
   end loop for_loop;
   
   control_input.active_driver <= "000";
@@ -76,7 +79,11 @@ 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;
+
   wait for 5 * cycle;
+  reset <= '1';
+
   report "Monitor process done";
   wait;
 end process monitor_proc;
diff --git a/src/io_type_pkg.vhd b/src/io_type_pkg.vhd
index ff8c6c6..ea50409 100644
--- a/src/io_type_pkg.vhd
+++ b/src/io_type_pkg.vhd
@@ -23,13 +23,14 @@ package io_types is
     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: std_logic;
+    ready, is_write: std_logic;
   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;
   end record control_unit_in_t;
   --- PROTOCOL INFORMATION ---
   constant interface_inst : interface_inst_t := (