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Hi Jerry,
This explanation is not clear, so let me ask it more directly;
Are you trying to use multiple transceiver receiver channels to capture pulse events?
Why are you using a second FPGA, when the Arria could do the work? If you must send data between the two FPGAs, then the Arria should create data packets, and use a "standard" transport protocol between it and the Stratix device.
You need a "master reference" signal.
For example, lets say you had 4 receiver channels that you needed to align. One way to align them is to connect them to a common source, eg., a single transmitter channel that is split 4 ways. Since the transmitter channel is sending a common signal to all four receivers, then any misalignment in the receivers must be due to their receiver deserialization logic. So you "swallow" bits until they align.
Your measurement system input needs to incorporate a multiplexer so that you can look at the transmitter channel after power-on to align the receivers, and then switch to the pulsed signals that you are trying to measure and timestamp.
Cheers,
Dave
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Hi Dave:
1. My project doesn't use GXB process pulse event. GXB is used to transmit&receive data. The pulse like "trigger" signal, which enable my logic to process the data from ADC. There also has one TDC channel used alone with each ADC channel. The TDC is used to measure the pulse's "arrival time", which will get a timestamp as i said. The trasmitter in ArriaGX send the data combing with the processed ADC data and the TDC's measuring result together to StratixIVGX. So there seems be one event data should be sent out from ArriaGX to StratixIVGX when each pulse come. Because all data process stages are synchronized, i think each ADC channel's data should arrive at StartixIVGX at the same time if the pulse arrive at dfferent ArriaGX at the same time.
2. Because there are total 22 reciever channels, so the another board must use StratixIVGX. Actually, we have 11 same ArriaGX boards, each board solders two same ArriaGX. Each ArriaGX implements one channel transmitter, these 11 ArriaGX total have 22 transmitter channels. This is why we use one StratixIV chip to hold all 22 channels' data.
3, I have done a simple test. Different transmitters in different chips, send data at the same time, the receiver side will get data with offset between these two channel. But it seems the offset is constant after power-on or reset. The offset may vary if you reset or power-on again. But, I don't know if this can prove the offset should be alsways constant after power-on? It shouldn't be constant according our real system test, however, i watch long time using simple project thru SignalTap and get a constant value offset.
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