Static temperature flows (STF) and dynamic temperature flows (DTF) have different processes for successful link bring up.
The DTF link bring up flow is used in real time scenarios to compensate for dynamic temperature conditions. Unlike STF, DTF link bring up runs continuous adaptation to maintain link performance over the dynamic temperature conditions. Configure the PMA parameters before running initial adaptation and continuous adaptation to extend the adaptive range of PMA in DTF link bring up.
Note: In DTF and STF modes, initial adaptation is run in internal serial loopback mode to calibrate the AFE parameters.
Note: In DTF and STF modes, initial adaptation is run in mission mode to calibrate AFE parameters with regards to the connected ISI channel.
Always run continuous adaptation after the following; performing the steps in this order is a must to get the PMA in the correct state:
- Internal serial loopback followed by initial adaptation
- Mission mode followed by initial adaptation
Note: When the device is in mission mode with continuous adaptation running and the ISI channel is changed, rerun initial adaptation. If the CDR lock does not assert or an unexpectedly high BER is recorded, perform a PMA analog reset. Refer to PMA reset for more details.
Note: Completion of initial adaptation can be read out by polling the PMA register. For more details refer to the PMA Register Map.
Note: During PMA performance verification testing, with continuous adaptation running in background, error bits cannot be accumulated to calculate BER because the Hard PRBS error counter is in a busy state. You can read errors during continuous adaptation by implementing a soft PRBS generator and verifier. Errors can be accumulated in hard PRBS error counter after stopping the continuous adaptation.
Note: When you generate and verify a pattern with logic, you can ignore the freeze continuous adaptation step in the dynamic temperature flow.