L99PM72PXP datasheet(39/128 Pages) STMICROELECTRONICS

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L99PM72PXP

Detailed description

Doc ID 023553 Rev 3

39/128

bus was in recessive (high) state or dominant (low) state. In order to wake up the

L99PM72PXP, the following criteria must be fulfilled:

●

The CAN interface wake-up receiver must receive a series of two consecutive valid

dominant pulses, each of which must be longer than 2 µs

●

The distance between 2 pulses must be longer than 2 µs.

●

The two pulses must occur within a time frame of 1.0 ms

Note:

A wake up caused by a message on the bus starts the voltage regulator and the

microcontroller to switch the application back to normal operation mode.

Figure 21.

CAN wake up capabilities

Note:

Pictures above illustrate the wake up behaviour from V1_standby Mode. For wake up from

VBat_standby Mode the NRESET signal (with 2 ms timing) is generated instead of the

RXDL(Interrupt) signal.

Wakeup by CAN Frame (WUF)

Wake from CAN TRX_STBY

If the CAN transceiver is in STBY the CAN frame detection logic is active.

In case of a valid wake up frame the Interrupt on pin RxDC is generated and the WUF flag

for wake up identification is set. There is no automatic state transition from CAN Transceiver

point of view. After serving the interrupt the micro can bring the CAN Transceiver into

TRX_NORMAL by setting CAN_ACT = 1 (CR 4).

Wake up from TRX_SLEEP

If the CAN Transceiver is in TRX_SLEEP mode the CAN frame detection logic is disabled.

The wake up can be done in two steps. To enable the CAN frame detection logic a wake up

L99PM72PXP Datasheet(PDF) 39 Page - STMicroelectronics