TLE9255WLC datasheet(40/100 Pages) INFINEON

40 / 100 page

Data Sheet

Rev. 1.02 2018-02-02

TLE9255W

CAN Partial Networking

Partial networking allows to exclude nodes from the CAN communication in a CAN network. If the TLE9255W

is in the Selective Wake Sub-Mode, then a CAN frame can wake-up the TLE9255W. This feature is called

selective wake and the CAN frame is called wake-up frame (WUF). The selective wake unit implements the

selective wake feature.

7.1

Wake-up frame evaluation

For a WUF detection the TLE9255W evaluates, whether a received CAN frame is a valid wake-up frame. This

wake-up frame evaluation consists of the following parts:

•CAN ID evaluation

• Frame data length code (DLC) and data field evaluation

If both parts are evaluated successfully AND if the CRC of the CAN Frame is valid, then a valid wake-up frame

is detected (see Figure 36). The following chapter describes the process in more detail.

Figure 36

WUF detection

7.1.1

Wake-up frame identifier evaluation

If all relevant CAN ID bits of a CAN frame match the configured CAN ID bits in the TLE9255W, then a valid WUF

CAN ID is received. The CAN ID mask excludes CAN ID bits from the evaluation. The CAN ID bits of a received

CAN frame are compared bit by bit with the CAN ID configured in register SWK_ID0_CTRL to SWK_ID3_CTRL. If

the received CAN ID is equal to the configured CAN ID, then the wake-up frame identifier evaluation is

successful. The CAN ID mask (registers SWK_MASK_ID0_CTRL to SWK_MASK_ID3_CTRL) defines which bits the

comparison considers. Figure 37 shows an example of the CAN ID evaluation (11 bit CAN ID). The green

background color defines the CAN ID bits which are not considered in the comparison.

CRC Field

ACK

EOF

CAN Frame

Wake-up detected

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