L9965T datasheet(42/62 Pages) STMICROELECTRONICS

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Note:

After a wakeup frame, an interframe time of at least 20 µs should be considered before sending any other

frames.

Table 38. IC reaction to WAKEUP frame

IC STATE

IC reaction upon frame receipt

NORMAL

•

L9965T/TS answers to SPI frame as described in Section 5.8.2.1, Section 5.8.2.2, or

Section 5.8.2.3

CYCLIC_WAKEUP

CYCLIC_COUNT

•

Device moves to NORMAL within TVIF_WAKEUP_TIME

•

The sender/listener states of the L9965T is latched in the WAKEUP_CYCLIC_TRX_SENDER

•

Or WAKEUP_CYCLIC_TRX_LISTENER bits in register GEN_STATUS2

•

GEN_STATUS2.WAKEUP_FAULT_SPI = 1

•

The frame is not decoded

DEEPSLEEP

•

Device moves to NORMAL within TVIF_WAKEUP_TIME

•

GEN_STATUS2.WAKEUP_FAULT_SPI = 1

•

The frame is not decoded

5.8.3.3

SPI GO2SLEEP command

This command can be sent by MCU SPI writing the data 0xCC in SPECIAL_REG to put the L9965T/TS in SLEEP

state. If the address of the frame is for broadcast write, the device sends a proper tone on daisy-chain to put the

whole chain in SLEEP state and then it moves to SLEEP state.

Note:

After GOTOSLEEP frame an interframe time of at least 20 µs should be considered before sending any other

frame.

Table 39. IC reaction to GO2SLEEP Frame

IC STATE

IC reaction upon frame receipt

NORMAL

•

If sent only to Transceiver DEV_ID, L9965T will move to DEEP SLEEP state if the

CYCLIC_WAKEUP is not enabled. In case the CYCLIC_WAKEUP is enabled will move to CYCLIC

COUNT state.

•

If sent as broadcast frame, the L9965T will propagate the GO2SLEEP tone on the VIF and then

moves to SLEEP state

CYCLIC_WAKEUP

CYCLIC_COUNT

•

Device moves to NORMAL within TVIF_WAKEUP_TIME.

•

The sender/listener states of the L9965T is latched in the WAKEUP_CYCLIC_TRX_SENDER

•

Or WAKEUP_CYCLIC_TRX_LISTENER bits in register GEN_STATUS2

•

GEN_STATUS2. WAKEUP_FAULT_SPI = 1

•

The frame is not decoded

DEEPSLEEP

•

Device moves to NORMAL within TVIF_WAKEUP_TIME.

•

GEN_STATUS2. WAKEUP_FAULT_SPI = 1

•

The frame is not decoded

5.8.3.4

SPI Default frame

Since the protocol is out of frame, the first answer issued by the IC when, after a wakeup condition, it moves to

NORMAL from DEEP SLEEP, CYCLIC COUNT or CYCLIC_WAKEUP state is the frame 0x0000000010.

Table 40. SPI Default frame

DEV_ID

0x00

Address feedback

0x00

DATA read

0x00

CRC

0x10

L9965T/L9965TS

Functional description

DS14987 - Rev 1

page 42/62

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