15.1.2.8 WRERR Bit

The WRERR bit can be used to determine if a write error occurred. WRERR will be set if one of the following conditions occurs:
  • If WR is set while the NVMADRH:NMVADRL points to a write-protected address
  • A Reset occurs while a self-write operation was in progress
  • An unlock sequence was interrupted

The WRERR bit is normally set by hardware, but can be set by the user for test purposes. Once set, WRERR must be cleared in software.

Table 15-3. Actions for PFM When WR = 1
FreeLWLOActions for PFM When WR = 1Comments
1xErase the 32-word row of NVMADRH:NVMADRL location
  • If WP is enabled, WR is cleared and WRERR is set
  • All 32 words are erased
  • NVMDATH:NVMDATL is ignored
01Copy NVMDATH:NVMDATL to the write latch corresponding to NVMADR LSBs
  • Write protection is ignored
  • No memory access occurs
00Write the write-latch data to PFM row
  • If WP is enabled, WR is cleared and WRERR is set
  • Write latches are reset to 0x3FFF
  • NVMDATH:NVMDATL is ignored