L9965TS datasheet(17/62 Pages) STMICROELECTRONICS

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Figure 8. CYCLIC_WAKEUP operation

The CYCLIC_WAKEUP state can be divided in three phases:

1. Transition phase from CYCLIC_COUNT to CYCLIC_WAKEUP state.

2. Diagnostic phase

3. CYCLIC_WAKEUP tone generation (see Section 5.8.3.7). CYCLIC_WAKEUP tone is generated only if there

aren’t fault recorded during diagnostic phase.

During CYCLIC_WAKEUP state every VIF data frame is not recognized by the device, and only FAULT/WAKEUP

tones (see Section 5.8.3.8) and SPI wakeup commands (see Section 5.8.3.2) are accepted.

Device reaction to incoming wake-up tones from VIF or from SPI Target are the following:

•

During transition phase from CYCLIC_COUNT to CYCLIC_WAKEUP state: IC moves to NORMAL and

sets FLT and WKP outputs (depending on the setting of WKP pin, see Section 5.9.3). Device never

completes the CYCLIC_WAKEUP phase.

•

During diagnostic phase: IC moves to NORMAL state (it becomes again sensitive to VIF communication)

and sets FLT and WKP outputs (depending on the setting of WKP pin, see Section 5.9.3); diagnostic

routine continues until completion.

•

During CYCLIC_WAKEUP tone generation device moves to NORMAL state.

5.1.2.2

CYCLIC_WAKEUP State diagnostics

During the CYCLIC_WAKEUP state the following diagnostics are automatically performed:

L9965T/L9965TS

Functional description

DS14987 - Rev 1

page 17/62

L9965TS Datasheet(PDF) 17 Page - STMicroelectronics