PROM #2 in the ERPB Trigger MTG

                   Timing Specification File

        Timing Specification File Revision:  18-MAR-1994 (DE original write)
                                             16-JUN-1994 (SG fix a comment,
                                                          no change in PROMs)
                                             26-JUL-1994 (DE fix the
                                                          misslabeled comments
                                                          for Ch #15 and #16.
                                                          no change in PROMs)


            PROM Timing Waveform Serial Number:  2A









PROM 2 of the ERPB MTG supplies the signals for MTG channels 9 through 16.

All numeric data in all Timing Specification Files is in decimal.

This is the revision A file for this PROM.

The only signals produced by this PROM are used to load the logic cell
arrays on the ERPB cards.  No information is stored in channels #9 through
#13 of the PROM.  Channels #14 through #16 hold the timing pattern that
loads the logic cell arrays.  This pattern is NOT "played" repetitively
at each beam crossing cycle.  It is only "played"  with the MTG in single
sweep mode when the logic cells need to be loaded.  To emphasize this the
Load LCA timing pattern will be stored between PROM Addresses 1000 and 2000.

Note that this PROM can also be used in PROM locations #3 and #4 on the
ERPB MTG  i.e.  ERPB's for |eta|=9:16 and |eta|=17:20.



    Channel                   Function
   ---------    ------------------------------------------------------------
       9.         Not Used
      10.         Not Used
      11.         Not Used
      12.         Not Used
      13.         Not Used

      14.         Load LCA Signal #1
      15.         Load LCA Signal #2
      16.         Load LCA Signal #3





Page  2


Loading the Logic Cell Arrays
-----------------------------

The signal names are the following:

   Load_LCA_1   This is the MIDDLE signal on Steve Pier's CONF_00.tim timing
                diagram and is carried on DIST Cap Timing input cable
                pins 23-24 named MTG_7.

   Load_LCA_2   This is the BOTTOM signal on Steve Pier's CONF_00.tim timing
                diagram and is carried on DIST Cap Timing input cable
                pins 25-26 named MTG_8.

   Load_LCA_3   This is the TOP signal on Steve Pier's CONF_00.tim timing
                diagram and is carried on DIST Cap Timing input cable
                pins 27-28 named MTG_9.

Stable state before loading is:  All three lines are high.

To Load the LCA's:  Bring signals Load_LCA_1 and Load_LCA_2 low.
                    Wait 3 usec and bring signal Load_LCA_3 low.
                    Wait 3 usec and bring signal Load_LCA_3 high.  loads a 0
                    Wait 3 usec and bring signal Load_LCA_1 high.
                    Wait 3 usec and bring signal Load_LCA_3 low.
                    Wait 3 usec and bring signal Load_LCA_3 high.  loads a 1
                    Wait 3 usec and bring signal Load_LCA_2 high to finish.
                    All three signals are back in the high state.



Beginning_of_Data_Section


; ERPB MTG Channel #9 is not used.

Channel #9,  Down_At 0        ; Not Used.


; ERPB MTG Channel #10 is not used.

Channel #10,  Down_At 0        ; Not Used.


; ERPB MTG Channel #11 is not used.

Channel #11,  Down_At 0        ; Not Used.


; ERPB MTG Channel #12 is not used.

Channel #12,  Down_At 0        ; Not Used.


; ERPB MTG Channel #13 is not used.

Channel #13,  Down_At 0        ; Not Used.




; ERPB MTG Channel #14 is the Load_LCA_Signal_1

Channel #14,  Up_At 0,  Down_At 1001,  Up_At 1301



; ERPB MTG Channel #15 is the Load_LCA_Signal_2

Channel #15,  Up_At 0,  Down_At 1001,  Up_At 1601



; ERPB MTG Channel #16 is the Load_LCA_Signal_3

Channel #16,  Up_At 0,  Down_At 1101,  Up_At 1201,  Down_At 1401,  Up_At 1501



End_of_Data_Section