Updated rx buffer to integer instead of natural to allow

for negative values.

src/lib/can_components.vhd

@@ -321,12 +321,12 @@ package can_components is
         signal inc_extra_wr_ptr       :in     std_logic;
         signal read_increment         :in     std_logic;
         signal drv_bus                :in     std_logic_vector(1023 downto 0);
-        signal read_pointer           :out    natural range 0 to buff_size - 1;
-        signal read_pointer_inc_1     :out    natural range 0 to buff_size - 1;
-        signal write_pointer          :out    natural range 0 to buff_size - 1;
-        signal write_pointer_raw      :out    natural range 0 to buff_size - 1;
-        signal write_pointer_extra_ts :out    natural range 0 to buff_size - 1;
-        signal rx_mem_free_int        :out    natural range -1 to buff_size + 1
+        signal read_pointer           :out    integer range 0 to buff_size - 1;
+        signal read_pointer_inc_1     :out    integer range 0 to buff_size - 1;
+        signal write_pointer          :out    integer range 0 to buff_size - 1;
+        signal write_pointer_raw      :out    integer range 0 to buff_size - 1;
+        signal write_pointer_extra_ts :out    integer range 0 to buff_size - 1;
+        signal rx_mem_free_int        :out    integer range -1 to buff_size + 1
     );
     end component;
 

src/rx_buffer/rx_buffer.vhd

@@ -309,32 +309,32 @@ architecture rtl of rx_buffer is
     ----------------------------------------------------------------------------
 
     -- Read Pointer (access from SW)
-    signal read_pointer             :       natural range 0 to buff_size - 1;
+    signal read_pointer             :       integer range 0 to buff_size - 1;
 
     -- Read pointer incremented by 1 (combinationally)
-    signal read_pointer_inc_1       :       natural range 0 to buff_size - 1;
+    signal read_pointer_inc_1       :       integer range 0 to buff_size - 1;
 
     -- Write pointer (committed, available to SW, after frame was stored)
-    signal write_pointer            :       natural range 0 to buff_size - 1;
+    signal write_pointer            :       integer range 0 to buff_size - 1;
 
     -- Write pointer RAW. Changing during frame, as frame is continously stored
     -- to the buffer. When frame is sucesfully received, it is updated to
     -- write pointer!
-    signal write_pointer_raw        :       natural range 0 to buff_size - 1;
+    signal write_pointer_raw        :       integer range 0 to buff_size - 1;
 
     -- Extra write pointer which is used for storing timestamp at the end of
     -- data frame!
-    signal write_pointer_extra_ts   :       natural range 0 to buff_size - 1;
+    signal write_pointer_extra_ts   :       integer range 0 to buff_size - 1;
 
     -- Final pointer to memory. "write_pointer_raw" and 
     -- "write_pointer_extra_ts" are multiplexed based on RX FSM! 
-    signal memory_write_pointer     :       natural range 0 to buff_size - 1;
+    signal memory_write_pointer     :       integer range 0 to buff_size - 1;
 
     -- Data that will be written to the RX Buffer memory!
     signal memory_write_data        :       std_logic_vector(31 downto 0);
 
     -- Number of free memory words available to SW after frame was committed.
-    signal rx_mem_free_int          :       natural range -1 to buff_size + 1;
+    signal rx_mem_free_int          :       integer range -1 to buff_size + 1;
 
     ----------------------------------------------------------------------------
     ----------------------------------------------------------------------------

src/rx_buffer/rx_buffer_pointers.vhd

@@ -113,28 +113,28 @@ entity rx_buffer_pointers is
         -- Pointer outputs
         ------------------------------------
         -- Read Pointer (access from SW)
-        signal read_pointer         :out     natural range 0 to buff_size - 1;
+        signal read_pointer         :out     integer range 0 to buff_size - 1;
 
         -- Read pointer incremented by 1 (combinationally)
-        signal read_pointer_inc_1   :out     natural range 0 to buff_size - 1;
+        signal read_pointer_inc_1   :out     integer range 0 to buff_size - 1;
 
         -- Write pointer (committed, available to SW, after frame was stored)
-        signal write_pointer        :out     natural range 0 to buff_size - 1;
+        signal write_pointer        :out     integer range 0 to buff_size - 1;
 
         -- Write pointer RAW. Changing during frame, as frame is continously stored
         -- to the buffer. When frame is sucesfully received, it is updated to
         -- write pointer!
-        signal write_pointer_raw    :out     natural range 0 to buff_size - 1;
+        signal write_pointer_raw    :out     integer range 0 to buff_size - 1;
 
         -- Extra write pointer which is used for storing timestamp at the end of
         -- data frame!
-        signal write_pointer_extra_ts :out   natural range 0 to buff_size - 1;
+        signal write_pointer_extra_ts :out   integer range 0 to buff_size - 1;
 
         ------------------------------------
         -- Mem. free outputs
         ------------------------------------
         -- Number of free memory words available for user
-        signal rx_mem_free_int      :out    natural range -1 to buff_size + 1
+        signal rx_mem_free_int      :out    integer range -1 to buff_size + 1
 
     );
 end entity;
@@ -152,19 +152,19 @@ architecture rtl of rx_buffer_pointers is
     signal drv_erase_rx             :       std_logic;
 
     -- Raw value of number of free memory words.
-    signal rx_mem_free_raw          :       natural range -1 to buff_size + 1;
+    signal rx_mem_free_raw          :       integer range -1 to buff_size + 1;
 
     -- Number of free memory words calculated during frame storing before commit
     -- combinationally incremented by 1.
-    signal rx_mem_free_raw_inc_1    :       natural range -1 to buff_size + 1;
+    signal rx_mem_free_raw_inc_1    :       integer range -1 to buff_size + 1;
 
     -- Number of free memory words calculated during frame storing before commit
     -- combinationally decremented by 1.
-    signal rx_mem_free_raw_dec_1    :       natural range -1 to buff_size + 1;
+    signal rx_mem_free_raw_dec_1    :       integer range -1 to buff_size + 1;
 
     -- Number of free memory words available to SW, combinationally icnremented
     -- by 1.
-    signal rx_mem_free_int_inc_1    :       natural range -1 to buff_size + 1;
+    signal rx_mem_free_int_inc_1    :       integer range -1 to buff_size + 1;
 
 begin