Index: /firmware/FTU/FTU_control.vhd
===================================================================
--- /firmware/FTU/FTU_control.vhd	(revision 10050)
+++ /firmware/FTU/FTU_control.vhd	(revision 10051)
@@ -201,7 +201,4 @@
             ram_dia_sig <= (others => '0');
             FTU_control_State <= INIT_RAM;
-          --elsif (ram_ada_cntr = (NO_OF_ENABLE*RAM_ADDR_RATIO + NO_OF_COUNTER*RAM_ADDR_RATIO*RAM_CEF + (NO_OF_DAC - NO_OF_DAC_NOT_USED)*RAM_ADDR_RATIO) + 2) then  -- default CRC errors
-            --ram_dia_sig <= (others => '0');
-            --FTU_control_State <= INIT_RAM;
           elsif (ram_ada_cntr < 2**RAM_ADDR_WIDTH_A) then  -- empty RAM cells
             ram_dia_sig <= (others => '0');
@@ -276,5 +273,5 @@
           end if;
 
-        when CONFIG_COUNTER =>
+        when CONFIG_COUNTER =>  -- set prescaling value for counters
           wait_cntr <= wait_cntr + 1;
           new_rates_busy <= '1';
@@ -296,5 +293,5 @@
           end if;
           
-        when CONFIG_ENABLE =>
+        when CONFIG_ENABLE =>  -- set enable patterns for sum trigger stage
           ram_enable_cntr <= ram_enable_cntr + 1;
           new_rates_busy <= '1';
@@ -302,9 +299,4 @@
             ram_adb_sig <= conv_std_logic_vector(ram_enable_cntr + 1, RAM_ADDR_WIDTH_B);
             FTU_control_State <= CONFIG_ENABLE;
-          --elsif (ram_enable_cntr > 0 and ram_enable_cntr < NO_OF_ENABLE + 1) then
-            --ram_adb_sig <= conv_std_logic_vector(ram_enable_cntr + 1, RAM_ADDR_WIDTH_B);
-            --enable_array_sig(ram_enable_cntr - 1) <= ram_dob;
-            --enables_ready <= '1';
-            --FTU_control_State <= CONFIG_ENABLE;
           elsif (ram_enable_cntr < NO_OF_ENABLE) then
             ram_adb_sig <= conv_std_logic_vector(ram_enable_cntr + 1, RAM_ADDR_WIDTH_B);
@@ -327,5 +319,5 @@
           end if;
           
-        when CONFIG_DAC =>
+        when CONFIG_DAC =>  -- start to set thresholds for sum trigger patches
           new_rates_busy <= '1';
           ram_dac_cntr <= ram_dac_cntr + 1;
@@ -354,5 +346,5 @@
           end if;
           
-        when CONFIG_DAC_WAIT =>
+        when CONFIG_DAC_WAIT =>  -- wait until setting of thresholds has finished
           if (config_ready = '1') then
             new_DACs_in_RAM <= '0';
@@ -591,5 +583,5 @@
           end if;
 
-        when DO_PING_PONG =>  -- just answer to FTM 
+        when DO_PING_PONG =>  -- answer to FTM and send DNA
           wait_cntr <= wait_cntr + 1;
           if (wait_cntr = 0) then
@@ -605,13 +597,4 @@
     end if;
   end process FTU_control_FSM;
-
-  --detect_new_rates: process(new_rates, new_rates_busy)
-  --begin
-    --if(new_rates_busy = '1') then
-      --new_rates_sig <= '0';
-    --elsif rising_edge(new_rates) then
-      --new_rates_sig <= '1';
-    --end if;
-  --end process detect_new_rates;
 
   detect_new_rates: process(clk_50MHz)
Index: /firmware/FTU/FTU_top.vhd
===================================================================
--- /firmware/FTU/FTU_top.vhd	(revision 10050)
+++ /firmware/FTU/FTU_top.vhd	(revision 10051)
@@ -58,5 +58,5 @@
     sck           : OUT STD_LOGIC;                  -- serial clock to DAC
     mosi          : OUT STD_LOGIC;                  -- serial data to DAC, master-out-slave-in
-    clr           : OUT STD_LOGIC;                  -- clear signal to DAC
+    clr           : OUT STD_LOGIC;                  -- clear signal to DAC, not used
     cs_ld         : OUT STD_LOGIC;                  -- chip select or load to DAC
     
Index: /firmware/FTU/ftu_definitions.vhd
===================================================================
--- /firmware/FTU/ftu_definitions.vhd	(revision 10050)
+++ /firmware/FTU/ftu_definitions.vhd	(revision 10051)
@@ -60,5 +60,5 @@
   constant CNTR_FREQ_DIVIDER : integer :=    25000;  -- for simulation, should normally be 1 
     
-  --32byte dual-port RAM, port A: 8byte, port B: 16byte
+  --64byte dual-port RAM, port A: 8byte, port B: 16byte
   constant RAM_ADDR_WIDTH_A : integer := 6;
   constant RAM_ADDR_WIDTH_B : integer := 5;
Index: /firmware/FTU/rs485/FTU_rs485_control.vhd
===================================================================
--- /firmware/FTU/rs485/FTU_rs485_control.vhd	(revision 10050)
+++ /firmware/FTU/rs485/FTU_rs485_control.vhd	(revision 10051)
@@ -247,5 +247,5 @@
       case FTU_rs485_control_State is
 
-        when INIT =>
+        when INIT =>  -- reset CRC register
           reset_crc_sig <= '1';
           FTU_rs485_control_State <= RECEIVE;
@@ -373,5 +373,5 @@
           end if;
 
-        when SET_DAC_WAIT_2 =>
+        when SET_DAC_WAIT_2 =>  -- wait one cycle for CRC calculation
           crc_enable_sig <= '0';
           FTU_rs485_control_State <= SET_DAC_TRANSMIT;
@@ -396,5 +396,5 @@
           end if;
 
-        when SET_ENABLE_WAIT_2 =>
+        when SET_ENABLE_WAIT_2 =>  -- wait one cycle for CRC calculation
           crc_enable_sig <= '0';
           FTU_rs485_control_State <= SET_ENABLE_TRANSMIT;
@@ -417,5 +417,5 @@
           end if;
 
-        when SET_PRESCALING_WAIT_2 =>
+        when SET_PRESCALING_WAIT_2 =>  -- wait one cycle for CRC calculation
           crc_enable_sig <= '0';
           FTU_rs485_control_State <= SET_PRESCALING_TRANSMIT;
@@ -444,5 +444,5 @@
           end if;
 
-        when READ_RATES_WAIT_2 =>
+        when READ_RATES_WAIT_2 =>  -- wait one cycle for CRC calculation
           crc_enable_sig <= '0';
           FTU_rs485_control_State <= READ_RATES_TRANSMIT;
@@ -468,5 +468,5 @@
           end if;
 
-        when READ_DAC_WAIT_2 =>
+        when READ_DAC_WAIT_2 =>  -- wait one cycle for CRC calculation
           crc_enable_sig <= '0';
           FTU_rs485_control_State <= READ_DAC_TRANSMIT;
@@ -491,5 +491,5 @@
           end if;
 
-        when READ_ENABLE_WAIT_2 =>
+        when READ_ENABLE_WAIT_2 =>  -- wait one cycle for CRC calculation
           crc_enable_sig <= '0';
           FTU_rs485_control_State <= READ_ENABLE_TRANSMIT;
@@ -512,5 +512,5 @@
           end if;
 
-        when READ_PRESCALING_WAIT_2 =>
+        when READ_PRESCALING_WAIT_2 =>  -- wait one cycle for CRC calculation
           crc_enable_sig <= '0';
           FTU_rs485_control_State <= READ_PRESCALING_TRANSMIT;
@@ -532,5 +532,5 @@
           end if;
 
-        when PING_PONG_WAIT_2 =>
+        when PING_PONG_WAIT_2 =>  -- wait one cycle for CRC calculation
           crc_enable_sig <= '0';
           FTU_rs485_control_State <= PING_PONG_TRANSMIT;
Index: /firmware/FTU/rs485/FTU_rs485_interpreter.vhd
===================================================================
--- /firmware/FTU/rs485/FTU_rs485_interpreter.vhd	(revision 10050)
+++ /firmware/FTU/rs485/FTU_rs485_interpreter.vhd	(revision 10051)
@@ -110,5 +110,5 @@
       case FTU_rs485_interpreter_State is
 
-        when INIT =>
+        when INIT =>  -- reset CRC register
           reset_crc_sig <= '1';
           FTU_rs485_interpreter_State <= WAIT_FOR_DATA;
@@ -134,9 +134,9 @@
           reset_crc_sig <= '0';
 
-        when WAIT_CRC =>
+        when WAIT_CRC =>  -- wait one cycle for CRC calculation
           crc_enable_sig <= '0';
           FTU_rs485_interpreter_State <= CHECK_CRC;
           
-        when CHECK_CRC =>
+        when CHECK_CRC =>  -- check whether CRC matches
           reset_crc_sig  <= '1';
           if (crc_match_sig = '1') then
