I have finished the first version of the stop master design based
on our last meeting last month at Caltech. The following message
is trying to tell you what it does. Please read it and send all
your comments or any good ideas to me. If you have any question
which I probably havn't described clearly in this following mail,
please tell me. I plan to make an ACTEL chip later this week.
--Rongzhi
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W A V E F O R M S T O P M A S T E R
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1.) General Description
The circuit used Actel (A1010) FPGA to take care of both CAMAC interface
and digital part of the circuit itself.
The waveform stop will be generated at one millisecond after one of the
scintillator triggers happened. The scintillator triggers include
FMT (Fast Monopole Trigger)
ERP
CSPAM
LIP (Lightly ionization particle)
ST_MNP (Streamer Tube MoNoPole trigger)
Caltech MNP (Caltech Slow Monopole trigger)
For Caltech Slow monopole trigger, there are some more details should be
taken care of such as face coincidence and time info for the trigger from
each different face. Therefore, there are total five inputs for the Caltech
slow monopole trigger corresponding to BOTTOM, CENTER, TOP, WEST, AND NORTH
OR SOUTH faces.
All the time info is gotten by using an external clock with 16
Flip-Flops counter. Therefore, the period of the clock time can be
as short as 20ns, which we probably don't need. The one
millisecond delay is controlled by 14 bits external switch. It
allows to choose whatever time we want. (Note that the flip-flop
counters have been synchronized.)
2.) CAMAC FUNCTION
F = 9 ---> CLEAR EVERYTHING
F = 2 ---> READ
F = 3 ---> READ
CAMAC FUNCTION TO READ THE TRIGGER TIME FOR DIFFERENT TRIGGER TYPE
F:2 A:0 UNCONNECTED PINT 8
F:2 A:1 CALTECH SLOW MONOPOLE
F:2 A:2 ERP
F:2 A:3 PMT
F:2 A:4 CSPAM
F:2 A:5 LIP1
F:2 A: ST_MNP (Streamer Tube monopole trigger)
F:2 A:7 spare for future use
F:2 A:8 spare for future use
``F'' is CAMAC function and ``A'' IS CAMAC ADDRESS.
Therefore, F:2 A:1 will read out the time info for caltech slow
mnp relative to the first trigger which is one of these eight
input trigger signals. But if it is the first trigger, the time is
ZERO. For those inputs which don't have trigger signals during 1ms
period, their times will count down to the full scale which is
1ms.
For the caltech slow monopole trigger, there are more information installed
such as face coincidence trigger and time information for the triggers from
different faces.
The following CAMAC function is to read the time information for
each faces for the caltech slow monopole trigger.
F:3 A:0 BOTTOM
F:3 A:1 CENTER
F:3 A:2 TOP
F:3 A:3 WEST
F:3 A:4 EAST
F:3 A:5 NORTH OR SOUTH
F:3 A:8 TELLS US WHICH TRIGGER HAPPENED, WHERE TOTAL 16 BITS STAND FOR
BIT 0: TOHM BOTTOM FACE
BIT 1: TOHM CENTER FACE
BIT 2: TOHM TOP FACE
BIT 3: TOHM WEST FACE
BIT 4: TOHM EAST FACE
BIT 5: TOHM NORTH OR SOUTH FACE
BIT 6: TOHM FACE COINCIDENCE TRIGGER
BIT 7: TOHM SINGLE FACE TRIGGER
BIT 8: ERP
BIT 9: FMT
BIT 10: CSPAM
BIT 11: LIP
BIT 12: SPARE
BIT 13: ST_MNP
BIT 14: SPARE
BIT 15: JUNK
The bit number is from low to high as bits XXXX XXXX should be counted like
7654 3210.