GXB:tranceiver transmission time issue

Hi Jerry,

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My project, one board using two FPGA (ArriaGX) processing "pulse" events, which have ramdom timestamp. Another board using single FPGA (Stratix IVGX) receive the processed data and sort those events according timestamp.

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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?

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Given a GXB channel, if each event transmission with ramdom offset, it's difficult for StratixIV to sort those events.

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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.

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If the offset is a constant value after power-on, it seems i could make padding to compensate this transmission offset in different lanes. But, as you said, different lanes should have arbirary offset. Also according my first post JPG shows, it should be ramdom offset. I really don't know how to align them?

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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