SLLA521B January   2022  – June 2022 TCAN1145-Q1 , TCAN1146-Q1

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction – Partial Networking
  4. 2Partial Networking Application
    1. 2.1 Modes of Operation and Partial Networking
    2. 2.2 Sleep Mode and Partial Networking
    3. 2.3 Wake-Up Frame
    4. 2.4 Classical High-speed CAN, CAN FD, and PN
    5. 2.5 Mixed Network Information
  5. 3CAN Frames and Wake-up Frames
    1. 3.1 CAN Frame Structure
    2. 3.2 Wake-up Frames
      1. 3.2.1 ID Field Match
      2. 3.2.2 Data Length Code (DLC) Match
      3. 3.2.3 Data Match
      4. 3.2.4 CRC Match
      5. 3.2.5 Acknowledge Match
    3. 3.3 Error Counter
    4. 3.4 Selective Wake FD Passive
  6. 4Selective Wake Registers
  7. 5Configuring Partial Networking
    1. 5.1 Valid CAN Message ID Example
    2. 5.2 Valid Data Example
  8. 6Summary
  9. 7References
  10. 8Revision History

3.2.3 Data Match

The Data field match requires that at least one bit, located in any bit position and in any byte, must match as a 1 in both the received field and the register programmed field. If the DLC code is ‘b0000, such that there are no Data bytes, then the Data field match is considered a WUF Data match.

The order of the data bytes stored in the DATA7-DATA0 register fields are designated in a descending order, such that the last byte of the frame is always considered Byte 0, to correspond with the register DATA0.

Figure 3-3 Data Matching

For this example, with DLC=8, there are two bits that have matched a ‘1’ in both the received data byte and the configured DATAn byte. Since only one match is required, this is a valid WUF Data field.

Figure 3-4 DLC Value and Data Byte

Figure 3-4 shows the mapping of how data bytes are interpreted for different DLCs. The order of transmitted bytes is from left to right. For a DLC code of 4, for example, the incoming bytes received would be checked against the provisioned bytes in the order of Data3, Data2, Data1, and Data0.