Digital BCM Meeting, 2021 March 24
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Meeting time: 4:00pm Eastern We'll be using this LBNL zoom link for the meeting: https://lbnl.zoom.us/j/95645100291
- Discussion of options and tradeoffs of how TI connection is made to the VCU108
- General discussion
Participants: R. Michaels, B. Moffit, W. Gu, S. Li, E. Sichtermann, Y. Kolomensky, Y. Mei, A. Cuda
- Discussing how to make the TI connection
- William and Yuan discuss the TI_FMC schematic. William thinks the trigger signal will be what carries the start of the helicity gate
- In the CODA system, the sync/reset is used to zero the clock counter. This is how the timestamps are generated.
- The four lines on the QSFP are:
- RX/TX1: Trigger; 1.25GHz
- RX/TX2: Clock; 250 MHz
- RX/TX3: Sync; 250 MHz, Manchester encoded
- RX/TX4: Fiber loopback; 250 MHz, Manchester encoded. This is used to measure the cable length, but we could do without it by measuring the cable connection by hand.
- The GPIO connector on the VCU108 ought to be able to handle the 250 MHz signals, but couldn't support the 1.25GHz trigger signal.
- The "Samtec Bullseye" connector on the VCU108 can handle the 1.25GHz signal
- New development plan
- Yuan will develop an interface board which will connect to the Bullseye and the GPIO connectors, and this would then be able to support all TI functionality
- Since the TI QSFP connection will be done on the new interface board, we would have the option of using the VCU108 QSFP for the data connection