Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Using UniPHY leaving RUP and RDN unconnected for a DDR2 SDRAM controller

is there a way to implement a UniPHY DDR2 SDRAM controller leaving RUP and RDN pins unconnected i.e. without OCT?
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Nope. It doesn't. I set Output Termination to "series 50 Ohm (without calibration)" and disabled Input Termination "parallel 50 Ohm", but fitter stops reporting several errors of type:

- I/O "<name>" has a termination control block assignment, but does not use calibrated on-chip termination

- Output buffer atom "<name>" has port "<name>" connected, but does not use calibrated on-chip termination.

While if I leave the input/output termination with calibration enabled, compilation successfully completes (with critical warnings regarding unconnected RUP and RDN), but with a quick test with signalTap on the automatically generated example project it shows afi_cal_fail asserted.