RUNNING THE L1 FRAMEWORK AT 5 uSECONDS BEAM CROSSINGS --------------------------------------------------------- 16-OCT-1990 These are the modifications to the L1 Trigger Framework to make it run with 5 useconds between beam crossings. From Dan Green's 4-OCT-1990 meeting the following timing setup will be used for 5 usec beam crossings. There are 3 crossings spaced at 278 RF buckets and 1 beam crossing spaced at 279 RF buckets. Recall that there are 1113 RF buckets in the machine at 53.104 MHz. From the above: 278 / 2 = 139 i.e. we need to address 139 locations in the MTG PROM's and be able to address the 140th without causing a problem. Recall also that we have been starting the MTG PROM's at address $200 and stopping at address $25C. This will change so that the starting address is $1D2 and the last addressed location is $25C. $25C - $200 = $5C = 92 ---> 93 locatons addresses in the PROM's $25C - $1D2 = $8A = 138 ---> 139 locatons addresses in the PROM's To make the MTG's run at 3.5 usec we have been loading the following: MTG Function Address Data Loaded (Decimal) Function -------------------- --------------------- ----------------------- 34 0 $200 as the PROM ADRS 34 2 Counter PreSet 35 92 $25C as the PROM ADRS 36 2 Counter Terminal Count Now to run at 5 usec we must load: MTG Function Address Data Loaded (Decimal) Function -------------------- --------------------- ----------------------- 34 210 $1D2 as the PROM ADRS 34 1 Counter PreSet 35 92 $25C as the PROM ADRS 36 2 Counter Terminal Count There are the following PROM's in the MTG's at this time: MAIN TIMING MTG PROM #1. This is MTG Channels #1 through #8. All signals can stay at their current positions. Channel #2, IML LATCH CLOCK, must be held high (except for its active low pulse) through out the new range. The starting file for this is MTGROM13.DAT, the new file can be named MTGROM53.DAT. PROM #2. This is MTG Channels #9 through #16. All signal can stay at their current positions. Channel #9, SBSC COMMON INCREMENT CLOCK, must be help high (except for its active low pulse) through out the new range. The starting file for this is MTGROM14.DAT, the new file can be named MTGROM54.DAT. PROM #3. This is MTG Channels #17 through #24. No useful changes to make. PROM #4. This is MTG Channels #25 through #32. No useful changes to make. AUX TIMING MTG PROM #1. This is MTG Channels #1 through #8. The starting file for this is AUXMTG2A.DAT, the new file can be named AUXMTG52.DAT. Channels #1 through #4 are OK and require no changes. Channel #5 The SPECIFIC TRIGGER FIRED STROBE splits across the beam crossing. It needs the first 5 ticks that are High after the beam crossing moved to 1D2 through 1D6. Channel #6 The COMINT CLOCK needs to continue through out the new range. Add the following: 1D2, 1D3 are HIGH 1D4, 1D5, 1D6, 1D7, 1D8, 1D9 are LOW 1DA, 1DB, 1DC, 1DD, 1DE, 1DF are HIGH 1E0, 1E1, 1E2, 1E3, 1E4, 1E5 are LOW 1E6, 1E7, 1E8, 1E9, 1EA, 1EB are HIGH 1EC, 1ED, 1EE, 1EF, 1F0, 1F1 are LOW 1F2, 1F3, 1F4, 1F5, 1F6, 1F7 are HIGH 1F8, 1F9, 1FA, 1FB, 1FC, 1FD are LOW 1FE, 1FF, 200, 201, 202, 203 are HIGH 204, 205, 206, 207, 208, 209, 20A are LOW Channel #7 The FIRST FOUR TICKS, High 1D2 through 1D5. Channel #8 The LAST FOUR TICKS, High 259 through 25C. OK as is. PROM #2. This is MTG Channels #9 through #16. All channels are Direct- In-Test-Triggers. No changes are requires. PROM #3. This is MTG Channels #17 through #24. All channels are Direct- In-Test-Triggers. No changes are requires. PROM #4. This is MTG Channels #25 through #32. All channels are Direct- In-Test-Triggers. No changes are requires. BUSY MTG No PROM's ---> No changes made to the PROM's. START DIGITIZE MTG PROM #1. This is MTG Channels #1 through #8. Channel #1 stays as is. Channels #2 through #8 have a pulse that splists across the beam crossing. The 6 ticks that are High after the beam crossing should move to 1D2 through 1D7. The starting file for this is STRMTG1B.DAT, the new file can be named STRMTG5B.DAT. PROM #2. This is MTG Channels #9 through #16. This pulse splists across the beam crossing. The 6 ticks that are High after the beam crossing should move to 1D2 through 1D7. The starting file for this is STRMTG1A.DAT, the new file can be named STRMTG5A.DAT. PROM #3. This is MTG Channels #17 through #24. This pulse splists across the beam crossing. The 6 ticks that are High after the beam crossing should move to 1D2 through 1D7. The starting file for this is STRMTG1A.DAT, the new file can be named STRMTG5A.DAT. PROM #4. This is MTG Channels #25 through #32. This pulse splists across the beam crossing. The 6 ticks that are High after the beam crossing should move to 1D2 through 1D7. The starting file for this is STRMTG1A.DAT, the new file can be named STRMTG5A.DAT. HOLD TRANSFER MTG All PROM's are the same. All are OK. No changes are necessary. Summary of the new changed PROM's: MAIN TIMING SIGNAL MTG replace the first 2 PROM's. AUX TIMING SIGNAL MTG replace the first PROM. START DIGITIZE MTG replace all 4 PROM's. Hex values to recall: $1D2 = 466 $200 = 512 $25C = 604 To be safe all new PROM's should hold the state of each channel for 5 extra ticks on both sides of the beam crossing (i.e. 5 ticks before 1D2 and 5 ticks after 25C.