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Altera_Forum's avatar
Altera_Forum
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16 years ago

Lock a clock to a 8B10B data stream?

Hi there, I am trying to find a way to synchronize a chain of equipments but don't want to use a dedicated clock network. If I use the transrecivers in Arria II GX to implement GIGE protoc...
Altera_Forum's avatar
Altera_Forum
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16 years ago

Another question (again my ignorance of GIGE). Is it really necessary to lock the clocks? I could see two other alternatives:

1 - Are you allowed to transmit NULL or "skip" characters in the middle of a packet or is it only allowed between packets. If you are allowed to transmit NULL characters, then I don't see where it's necessary to lock the clocks at all. If your reference clock is faster than the received data, you just transmit NULL characters between valid characters. If your clock is slower than the received data, you need a large enough FIFO to buffer the data. The size of the buffer depends on your packet length, the estimated difference between the clocks, and this of course assumes some inter-packet gap.

2 - Can you just buffer entire packets and retransmit them? Depending on the packet length and the gap between packets, this seems like the easiest solution.

Jake