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Altera_Forum
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14 years ago

ALTGX byte ordering?

I'm receiving data via the ALTGX PIPE interface (PCI Express). I'm seeing that the byte ordering is random. The Arria II GX handbook states (page 1-35) that "Byte Ordering Depending on when t...
Altera_Forum's avatar
Altera_Forum
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14 years ago

After having done additional research on this topic, I have found that I should swap the bytes when I receive a COM symbol on the lower byte of the 16-bit data. The compliance pattern is 4 symbols long and is sent with the COM symbol first so should be received with the COM symbol in the LSByte on the pipe interface. When receiving one of the ordered sets, the same applies.

I have verified and this works for the compliance pattern. I have yet to validate the functionality with actual ordered sets but should work too.