src/fifo_buffer/fifo_buffer.vhd

@@ -20,7 +20,8 @@ entity fifo_buffer is
     valid_in : in std_logic;
     valid_out : out std_logic;
     data_in : in std_logic_vector(data_width - 1 downto 0);
-    data_out : out std_logic_vector(data_width - 1 downto 0)
+    data_out : out std_logic_vector(data_width - 1 downto 0);
+    used_slots  : out integer range 0 to buffer_size
   );
 end entity fifo_buffer;
 
@@ -73,6 +74,11 @@ begin
 comb_proc: process(write_pointer, read_pointer, buffer_full, valid_in, rst)
   variable write_pointer_inc : unsigned(address_bits - 1 downto 0);
 begin
+  if write_pointer >= read_pointer then
+    used_slots <= to_integer(unsigned(write_pointer) - unsigned(read_pointer));
+  else
+    used_slots <= buffer_size - to_integer(unsigned(read_pointer)) + to_integer(unsigned(write_pointer));
+  end if;
   ready_out <= not buffer_full;
   write_signal <= (valid_in and not buffer_full) or rst;
   write_pointer_inc := unsigned(write_pointer) + 1;

src/ganimede/ganimede.vhd

@@ -78,6 +78,7 @@ begin
   fifo_buffer_to_ip_inst : entity gan_buffer.fifo_buffer
     generic map (
       buffer_size => 1024
+      --tech => 60
     )
     port map(
       in_clk => socbridge_clk,
@@ -94,6 +95,7 @@ begin
   fifo_buffer_from_ip_inst : entity gan_buffer.fifo_buffer
     generic map (
       buffer_size => 1024
+--      tech => 60
     )
     port map(
       in_clk => clk, 
@@ -104,7 +106,8 @@ begin
       valid_in => ip_to_ganimede.socbridge.valid,
       valid_out => buffer_to_socbridge_driver.valid,
       data_in => ip_to_ganimede.socbridge.data,
-      data_out => buffer_to_socbridge_driver.data
+      data_out => buffer_to_socbridge_driver.data,
+      used_slots => buffer_to_socbridge_driver.used_slots
     );
     
   --- LATER WE ADD OPTIMIZATIONS HERE ---

src/ganimede/io_type_pkg.vhd

@@ -16,6 +16,7 @@ package io_types is
   type fifo_interface_t is record
     ready, valid : std_logic;
     data : std_logic_vector(fifo_width - 1 downto 0);
+    used_slots : integer;
   end record fifo_interface_t;
 
   type ext_protocol_def_t is record