[44] NVMC: Read after flash erase is unpredictable

This anomaly applies to IC Rev. Engineering A, build codes QFAA-AA0, QFAA-AC0, CGAA-AA0.

Symptoms

Reading flash after an erase operation returns invalid values.

Conditions

The flash page being read from was erased using NVMC.ERASEPAGE or NVMC.ERASEALL immediately before the read.

Consequences

Verifying a flash region is erased may fail. Writing to a flash page will never fail.

Workaround

Immediately after an erase operation, read from a page that was not erased in the operation, or write to any flash memory address. After one successful read or write, the symptom will not occur.

If ERASEALL was used, or it is not possible to identify which page was not erased in the operation, read from address 0x10000FFC after the erase operation as this is located in the FICR which is guaranteed to not be erased during the operation.


Documentation feedback | Developer Zone | Subscribe | Updated 2016-07-05