When the Data mask is enabled via the data mask bit, the data of the received frame must match the configured Data where at least one logic high (1) bit within the data field of the received frame matches a logic high (1) of the data field within the configured data. The relevant bit positions are determined by the configured Data in 8'h39 through 8'h40 and enabled by Data mask enable in 8'h38. An example of a matching and non-matching Data is shown in Figure 10-19
The selective wake data validation ensures that the last byte sent on the bus will be interpreted as data mask byte 0. This means for 8 bytes of data, the first byte sent is interpreted as data mask byte 7. For a DLC of 3, the last byte sent on the bus will be interpreted as data mask byte 0 and the first byte sent is interpreted as data mask byte 2. Below are a few examples of which bytes would be used for various bytes sent and received.