jlaitine opened a new pull request, #17411: URL: https://github.com/apache/nuttx/pull/17411
## Summary This improves the error detection logic for MPFS DDR training code. The original error checks were too restrictive, sometimes rejecting good training results. The issue was found on a larger production batch of devices, where some devices started failing to boot in extreme temperatures. 1) The CA training status vector don't need to be separated by 5 taps; this condition was copied originally from Microchip reference code (HSS), but also that has since changed. The values are *typically* separated like that, and it is an indication of good signal itegrity, but it is not a valid condition to reject the training results. 2) Add a check that the window offset + width doesn't exceed the whole range. If that occurs, either the training has failed completely, or the window is not properly centered. In the latter case, if it is consistent, one can apply offset to the window centering (RPC156) instead. ## Impact Affects MPFS builds which use NuttX as the bootloader (i.e. don't use HSS). This doesn't change the training procedure as such, only affects the pass/fail criteria for the extra sanity checks (additional checks to the controller's own). ## Testing Tested on custom MPFS design, with a batch of > 100 devices tested in temperature chamber. Observed some devices getting stuck at early boot in DDR training in temperatures below -20C, whereas after changes all work ok. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
