Created copies of chans 1 and 2 on chans 3 and 4 when opt and db9 rtms are used

642847e4 · Denia Bouhired-Ferrag · 42da5433 · 642847e4
Commit 642847e4 authored Oct 16, 2017 by Denia Bouhired-Ferrag
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conv_ttl_rs485.vhd top/conv_ttl_rs485.vhd +11 -1

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--- a/top/conv_ttl_rs485.vhd
+++ b/top/conv_ttl_rs485.vhd
@@ -471,7 +471,17 @@ begin
  -- Front and rear panel outputs
  ttl_o   <= pulse_out when sw_ttl = '1' else
             not pulse_out;
-  rs485_o <= pulse_out;
+  rs485_o (1 downto 0) <= pulse_out (1 downto 0);
+  -- Channels 3 and 4 output copies of chans 1 and 2 respectively
+  -- depending on RTMP Id of RTM connected.
+  --   *RTM with DB9 connectors has only 2 o/p channels in rs485 RTMP = Gnd Open Gnd
+  --   *Optical RTM only 2 o/p channels in optical RTMP= Open Open Gnd
+  -- in these cases channel 3 copies channel 1
+  --                channel 4 copies channel 2
+  -- 
+  rs485_o (3 downto 2) <= pulse_out (1 downto 0) when rtmp_i = "101" or rtmp_i = "100"
+                          else pulse_out (3 downto 2);
+  rs485_o (5 downto 4) <= pulse_out (5 downto 4);

  -- LED outputs
  -- Boards earlier than v4 do not use -ve logic for LEDs.