VME-NEW-IO

Use cases of existing VME-NIMIO32 board

Specs of the existing board:

• 6U VME single width
• VME A32/D32, firmware implements A24/D32 single word and A24/BLT32 block transfers. There is no VME drivers on the A-lines so cannot do MBLT64, 2eVME, 2eSST.
• Altera Cyclone1 FPGA, 6k LE, 180 i/o pins, 100-200 MHz clock speeds.
• 16 NIM inputs (convertable to TTL), LEMO connectors
• 16 ECL/LVDS inputs, LeCroy 4616 compatible ECL ribbon cable connector
• 16 NIM outputs, LEMO connectors
• 32 LEDs (one for each LEMO connector)

Main uses of the IO32 board have been:

• trigger latch, trigger timestamp and busy logic daq synchronization (LXe, IRIS, M11 test beams, DRAGON, ALPHA, EMMA, TRINAT, TREK, PTF, S1249 muonium production test, etc)
• scalers (16 ch, up to 200 MHz, deadtimeless) (most users)
• timestamp counter (4 ch, 100 MHz) (TRINAT, etc)
• 40MHz V1190 and 20MHz VF48 clock generator and trigger synchronization (LXe, IRIS, TREK, S1249, etc)
• V792 ADC gate and delay generator (M11 test beams, DRAGON, TRINAT, S1249, etc)
• custom trigger logic (M11 test beams, DRAGON, ALPHA, TRINAT, S1249)
• clock and trigger synchronization between 2 VME crates (DRAGON), 2 IO32 modules (TRINAT), separate DAQs (M11 beam tests)
• in addition there is a 1ns-time-bin delay-line TDC (never used)

Number of I/Os used:

• T2K/M11 beam tests - 8 NIM in, 8 NIM out
• S1249 muonium production test (M15) - 4 NIM in, 8 NIM out, (FIXME: ECL scalers?)
• ALPHA2 Si detector DAQ (CERN) - 16 NIM in, 16 NIM out
• DRAGON - 4 NIM in, 8 NIM out
• TRINAT TTL - (FIXME: 4 TTL in?)
• TRINAT - 8 NIM in, 8 NIM out
• TRINAT 2014 - 10 NIM in, 16 NIM out
• IRIS - ???
• TITAN EC (orchid) - 8 TTL in
• TREK, IRIS - 4 NIM in, 4 NIM out (trigger, busy, 40 MHz V1190 clock, 20 MHz VF48 clock)
• BNMR/BNQR - ?
• PTF - ?

Note: existing IO32 has significant delay from LEMO connector to FPGA logic (NIM-to-LVTTL converter, FPGA input pin,etc) and from FPGA logic to NIM output pin (FPGA output pin delay, LVTTL-to-NIM converter, etc). If using ECL inputs, add delay in NIM-to-ECL converter and in the ECL ribbon cable. FIXME: what is this delay?

Conclusion: for most common cases, 8 NIM in, 8 NIM out is sufficient.

Business case for new IO32 module

The existing IO32 module is very successful. Out of all 3+10+5=18 modules built, all are in use (including the 3 rev0 modules), none have failed. This module is easy to program and easy to use.

The main problem with existing modules is the small size of the Cyclone 1 FPGA - only 6000 logic elements. This limits the generic firmware can only 16 (out of 32 possible) scaler channels, only 4 timestamp channels, only 1 or 2 (out of 5) experiment-specific functions (custom trigger logic) and no space for a high resolution TDC, no space for a high capacity timestamp or time-sliced scaler (like the Struck/SIS3820).

Secondary problem is lack of high-speed data interface - the existing VME interface is limited to single-word or 32-bit block transfers (no drivers on the A-lines to permit 2eVME or 2eSST transfers).

If this module had a bigger FPGA and a high capacity data interface, it could be used to implement a 32-channel non-deadtime scaler or timestamp counter or a delay line or wavelet medium resolution TDC (1 ns time bin or better).

We have existing experiments that could use the timestamp and wavelet/delay line TDC functions right away - as low precision and medium precision TDCs - 5-10 ns and 200-1000 ps time bins - respectively - and possibly release some high precision V1190 TDC module.