31.5.3 Comparison Function on Received Character

Each time a valid character is received (without parity error and without frame error) it is compared to the wake-up trigger values. If the received character matches to the condition of wake-up, it is stored in the Receiver Holding register (RXLP_RHR), a system wake-up is generated and the RXLP is automatically disabled. If the character received does not match, it is ignored and the receiver continues to wait for a new valid start bit.

RXLP_CMPR (see RXLP Comparison Register) can be programmed to provide three different comparison methods:

• VAL1 equals VAL2—the comparison is performed on a single value and the wake-up request is generated if the received character equals VAL1.
• VAL1 is strictly lower than VAL2—any value between VAL1 and VAL2 generates a wake-up request.
• VAL1 is strictly higher than VAL2—the wake-up request is generated if either received character equals VAL1 or VAL2.