add batch normalization with unsigned values

This is needed for the first convolution layer, where MACs are done
with possible negative result. At the other layers we do XOR
with positive only results.

src/batch_normalization.vhd

@@ -8,7 +8,8 @@ library ieee;
 
 entity batch_normalization is
  generic (
- C_POST_CONVOLUTION_BITWIDTH : integer := 8
+ C_POST_CONVOLUTION_BITWIDTH : integer := 8;
+ C_UNSIGNED : integer range 0 to 1 := 1
  );
  port (
  isl_clk : in std_logic;
@@ -27,23 +28,47 @@ architecture behavioral of batch_normalization is
 
 begin
 
- proc_batch_normalization : process (isl_clk) is
- begin
+ gen_batch_normalization : if C_UNSIGNED = 1 generate
 
- if (rising_edge(isl_clk)) then
- sl_valid_out <= '0';
- slv_data_out(0) <= '0';
+ proc_batch_normalization : process (isl_clk) is
+ begin
 
- if (isl_valid = '1') then
- if (unsigned(islv_data) > unsigned(islv_threshold)) then
- slv_data_out(0) <= '1';
+ if (rising_edge(isl_clk)) then
+ sl_valid_out <= '0';
+ slv_data_out(0) <= '0';
+
+ if (isl_valid = '1') then
+ if (unsigned(islv_data) > unsigned(islv_threshold)) then
+ slv_data_out(0) <= '1';
+ end if;
+
+ sl_valid_out <= '1';
  end if;
+ end if;
+
+ end process proc_batch_normalization;
+
+ else generate
 
- sl_valid_out <= '1';
+ proc_batch_normalization : process (isl_clk) is
+ begin
+
+ if (rising_edge(isl_clk)) then
+ sl_valid_out <= '0';
+ slv_data_out(0) <= '0';
+
+ if (isl_valid = '1') then
+ if (signed(islv_data) > signed(islv_threshold)) then
+ slv_data_out(0) <= '1';
+ end if;
+
+ sl_valid_out <= '1';
+ end if;
  end if;
- end if;
 
- end process proc_batch_normalization;
+ end process proc_batch_normalization;
+
+ end generate gen_batch_normalization;
 
  oslv_data <= slv_data_out;
  osl_valid <= sl_valid_out;

src/window_convolution_activation.vhd

@@ -49,6 +49,16 @@ architecture behavioral of window_convolution_activation is
  constant C_POST_CONVOLUTION_BITWIDTH : integer := C_INPUT_CHANNEL_BITWIDTH + log2(C_KERNEL_SIZE ** 2 * C_INPUT_CHANNEL + 1) + 1;
  signal a_data_convolution : t_slv_array_1d(0 to C_OUTPUT_CHANNEL - 1)(C_POST_CONVOLUTION_BITWIDTH - 1 downto 0);
 
+ function is_batch_normalization_unsigned return integer is
+ begin
+
+ if (C_INPUT_CHANNEL_BITWIDTH = 1) then
+ return 1;
+ end if;
+
+ return 0;
+ end function is_batch_normalization_unsigned;
+
  signal slv_valid_batch_normalization : std_logic_vector(C_OUTPUT_CHANNEL - 1 downto 0);
  signal slv_data_batch_normalization : std_logic_vector(C_OUTPUT_CHANNEL * C_OUTPUT_CHANNEL_BITWIDTH - 1 downto 0);
  signal a_data_batch_normalization : t_slv_array_1d(0 to C_OUTPUT_CHANNEL - 1)(C_OUTPUT_CHANNEL_BITWIDTH - 1 downto 0);
@@ -106,7 +116,8 @@ begin
 
  i_batch_normalization : entity cnn_lib.batch_normalization
  generic map (
- C_POST_CONVOLUTION_BITWIDTH => C_POST_CONVOLUTION_BITWIDTH
+ C_POST_CONVOLUTION_BITWIDTH => C_POST_CONVOLUTION_BITWIDTH,
+ C_UNSIGNED => is_batch_normalization_unsigned
  )
  port map (
  isl_clk => isl_clk,