19.8.3 Peek Mode

Peek mode provides the least impact on CPU operation. In Peek mode, the scanner waits until the CPU does not need to access the NVM and ‘steals’ the instruction cycle to perform a scan. Program branching (GOTO, BRA, BRW), subroutine entry (CALL, CALLW), or returns from interrupts or subroutines (RETURN, RETFIE, RETLW) operations take two instruction cycles but do not access NVM, so the scanner may use one of those instruction cycles for scanning operations.

While Peek mode may have the least impact on CPU operation, the time required to complete the scan will vary depending on which instructions the CPU is executing.