Altera SerialLite II Protocol - Manual (Page 68)

68 Altera Corporation
SerialLite II Protocol Reference Manual
Data Link Layer Description
3. When the near receiver gets a valid ACK with an ID that it received
prior to the last eight segments, it causes the near transmitter to
resend all unacknowledged segments in sequence, beginning with
the segment containing the expected ID.
4. When the near receiver gets a valid NACK, it causes the near
transmitter to resend all unacknowledged segments in sequence,
beginning with the segment containing the expected ID.
5. When the near receiver gets an invalid ACK or an invalid NACK, it
does nothing. The link management segment is simply ignored. It
waits for a valid ACK or NACK to be re-sent when the segment
acknowledgement timer expires in the transmitter.
Table 2–24 summarizes the response to various transmission errors.
Figure 2–42 on page 2–69 shows an example of the retry-on-error
operation.
Table 2–24. Retry-on-Error Error Responses
Error Response
Invalid 8b/10b codes groups Far end transmitter issues NACK
Running disparity errors Far end transmitter issues NACK
Unsupported valid code groups Far end transmitter issues NACK
CRC errored packets with {EGP}
sequence Far end transmitter issues NACK
Out of order segment Far end transmitter issues NACK
Out of order acknowledgment Near end transmitter starts re-send