Forum Discussion
4 Replies
- Altera_Forum
Honored Contributor
Mind further elaborate what kind of phase synchronization that you are looking for? Generally in the transceiver channel, there is a phase comp FIFO which will help to compensate for phase different between the transceiver and fabric.
- Altera_Forum
Honored Contributor
I want to do the phase alignment between the ref_clk of the transmitted side and the recovery clock of CDR in the receiving side? I only found the frequency synchronization, but the initial phase in the receiving side is not same with the transmitted side. What's wrong for the Altera PHY?
- Altera_Forum
Honored Contributor
--- Quote Start --- I want to do the phase alignment between the ref_clk of the transmitted side and the recovery clock of CDR in the receiving side? I only found the frequency synchronization, but the initial phase in the receiving side is not same with the transmitted side. What's wrong for the Altera PHY? --- Quote End --- CDR is based on deriving clock from data transitions. Original absolute tx clock phase is unknown and is not carried in tx data. Tx data would have any offset from tx clock edge. Your request is unrealistic. - Altera_Forum
Honored Contributor
Agreed with kaz. Generally in a transceiver application, there will be ppm difference between the upstream and downstream devices. The CDR's recovered clock is depending on the incoming data transition and it is expected to have ppm and phase difference with the local TX clocks.