L9965TS datasheet(14/62 Pages) STMICROELECTRONICS

14 / 62 page

In a ring topology, a FLT pin interrupt is generated from both channels of L9965T within

NVIF_STACK*TVIF_WAKEUP_TIME timeout.

When the MCU is woken up by one channel of L9965T, it is supposed to wait also for the other channel to

generate the FLT pin interrupt to confirm the daisy-chain wakeup. If such event does not occur within the

NVIF_STACK*TVIF_WAKEUP_TIME timeout, the MCU shall run the VIF chain wakeup by MCU procedure.

Figure 6. Wakeup by fault of a daisy chain device

5.1.1.1.2

Wake-up via SPI

L9965T/TS can be woken up in DEEPSLEEP, CYCLIC_COUNT and CYCLIC_WAKEUP state by any valid SPI

frame issued by MCU on the SPI Target. A wakeup condition is acknowledged when the following pattern is

received:

1. A NCS high to low transition

2. 40 SCK pulses

3. A NCS low to high transition

The TSPI_WAKEUP_TIMEOUT is started upon every NCS assertion, and the wakeup pattern shall end before timeout

expiration, otherwise it is discarded.

L9965T/L9965TS

Functional description

DS14987 - Rev 1

page 14/62

L9965TS Datasheet(PDF) 14 Page - STMicroelectronics