added minus one for speed, Ingo

diff --git a/trb_net_obuf.vhd b/trb_net_obuf.vhd
index bb3caddaf929c56c8457d88d92f9d98fee64983c..ff2389a83756065b896a4baf79b4e6cd94d1fe50 100644 (file)
--- a/trb_net_obuf.vhd
+++ b/trb_net_obuf.vhd
@@ -70,6 +70,7 @@ architecture trb_net_obuf_arch of trb_net_obuf is
 
   signal CURRENT_DATA_COUNT, next_DATA_COUNT : STD_LOGIC_VECTOR (15 downto 0);
   signal max_DATA_COUNT, next_max_DATA_COUNT : STD_LOGIC_VECTOR (15 downto 0);
+  signal max_DATA_COUNT_minus_one, next_max_DATA_COUNT_minus_one : STD_LOGIC_VECTOR (15 downto 0);
   signal TRANSMITTED_BUFFERS, next_TRANSMITTED_BUFFERS : STD_LOGIC_VECTOR (1 downto 0);
   signal increase_TRANSMITTED_BUFFERS, decrease_TRANSMITTED_BUFFERS : STD_LOGIC;
 
@@ -110,7 +111,8 @@ architecture trb_net_obuf_arch of trb_net_obuf is
                                  CURRENT_DATA_COUNT,reg_SEND_ACK_IN,reg_INT_READ_OUT,
                                  INT_DATAREADY_IN, INT_DATA_IN, sent_ACK, sent_EOB,
                                  current_ACK_word,current_EOB_word, sbuf_free, sent_data,
-                                 max_DATA_COUNT,next_DATA_COUNT,
+                                 max_DATA_COUNT_minus_one,next_DATA_COUNT,
+                                 max_DATA_COUNT,
                                  next_TRANSMITTED_BUFFERS)
     begin  
       current_output_buffer <= current_NOP_word;
@@ -150,7 +152,7 @@ architecture trb_net_obuf_arch of trb_net_obuf is
       end if;
 --finally, block data read if the rec buffer is full
       if sent_data = '0' or
-        (next_DATA_COUNT = max_DATA_COUNT-1) or
+        (next_DATA_COUNT = max_DATA_COUNT_minus_one) or
         next_TRANSMITTED_BUFFERS(1) = '1'
       then           
         next_INT_READ_OUT       <= '0';
@@ -202,7 +204,7 @@ architecture trb_net_obuf_arch of trb_net_obuf is
   current_EOB_word(47 downto 0)   <= (others => '0');
   gen_sent_EOB : process (CURRENT_DATA_COUNT, max_DATA_COUNT)
     begin
-      if (CURRENT_DATA_COUNT = max_DATA_COUNT-1) then  
+      if (CURRENT_DATA_COUNT = max_DATA_COUNT_minus_one) then  
         sent_EOB <= '1';
       else
         sent_EOB <= '0';
@@ -221,6 +223,11 @@ architecture trb_net_obuf_arch of trb_net_obuf is
                            "0000000000010000" when REC_BUFFER_SIZE_IN="0011" else
                            "0000000000100000" when REC_BUFFER_SIZE_IN="0100" else
                            "0000000000000010";
+    next_max_DATA_COUNT_minus_one <= "0000000000000011" when REC_BUFFER_SIZE_IN="0001" else
+                           "0000000000000111" when REC_BUFFER_SIZE_IN="0010" else
+                           "0000000000001111" when REC_BUFFER_SIZE_IN="0011" else
+                           "0000000000011111" when REC_BUFFER_SIZE_IN="0100" else
+                           "0000000000000001";
 -- next_max_DATA_COUNT <= 2 ** (REC_BUFFER_SIZE_IN + 1);
     -- BUGBUG via pattern_gen
 
@@ -229,10 +236,10 @@ architecture trb_net_obuf_arch of trb_net_obuf is
     if rising_edge(CLK) then
       if RESET = '1' then
         max_DATA_COUNT <= (1 => '1', others => '0');
-      elsif CLK_EN = '1' then
-        max_DATA_COUNT <= next_max_DATA_COUNT;
+        next_max_DATA_COUNT_minus_one <= (0 => '1', others => '0');
       else
-        max_DATA_COUNT <= max_DATA_COUNT;
+        max_DATA_COUNT <= next_max_DATA_COUNT;
+        next_max_DATA_COUNT_minus_one <= next_max_DATA_COUNT_minus_one;
       end if;
     end if;
   end process;