When running internal code, external memory fails.

  • When the XA is powered up in internal mode, the external bus control pins are defaulted to quasi-bidirectional mode. This results in the control lines (RD-, WRL- & WRH-) failing to drive external hardware properly. These control line MUST be programmed to operate in Push-pull Mode via the PnCFGA & PnCFGB registers. Please refer to the data sheet for the XA on how to program these pins for push-pull operation.