The ID of the received frame matches the configured ID in all required bit positions. The relevant bit positions are determined by the configured ID in 8'h30 through 8'h33 and the programmed ID mask in 8'h34 through 8'h38. Classic Base Frame Format (CBFF) 11-bit Base ID and Classic Extended Frame Format (CEFF) 29-bit Extended ID and ID masks are supported. All masked ID bits except "do not care" must match exactly the configured ID bits for a WUF validation. If the masked ID bits are configured as "do not care" then both "1" and "0" are accepted in the ID. In the ID mask register a 1 represents “do not care”.
Figure 10-18 shows an example for valid WUF ID and corresponding ID Mask register