33902 datasheet(22/31 Pages) FREESCALE

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Analog Integrated Circuit Device Data

Freescale Semiconductor

33902

FUNCTIONAL DEVICE OPERATION

OPERATIONAL MODES

Distinction Between P_SPI and Traditional Operation.

The distinction between static device control and control

via P_SPI is performed by the duration of the EN and STBY

level. If the EN and STBY levels change before a time of

“tDEV-TR” then the device detects a P_SPI operation. If the EN

and / or STBY levels are stable for a time longer than 15

μs,

then the device state will be changed according to EN / STBY

level and device state diagram.

This means that the device mode change is done after a

delay of typ tDEV-TR and consequently the P_SPI frequency

operation should be faster than (1 / (2 * tDEV-TR).

With tDEV-TR = 8.0 μs, the SPI equivalent frequency should

be greater than 62.5 kHz.

End of P_SPI Message:

At the P_SPI message, the state of EN and STBY pins

should be in line with the device mode expectation:

example:

If the device is in Normal mode and should stay in Normal

mode after the P_SPI command, the EN and STBY pins

should be 1,1 at end of the P_SPI command.

If the device is in Listen Only mode, EN and STBY pins

should be 0,1, in order to set or maintain the device in Listen

Only mode.

Time between 2 P_SPI Message:

A min delay of 15

μs should be observed between two

P_SPI messages.

The delay is measured between the last transition of the

EN/STBY of the 1st message, and the 1st EN/STBY

transition of the next message.

P_SPI Availability:

The P_SPI is operating only in Normal and Listen Only

mode. It is not operating in Standby and Sleep modes.

Table 8 is the mapping of the P_SPI register.

Low power mode definition: Standby, Go To Sleep and

Sleep modes.

Table 8. P_SPI Bit Mapping

MOSI

STAR

ADRR

Rb/W

MOSI 4

MOSI 3

MOSI 2

MOSI 1

MOSI 0

MISO

ERR

ACK=ER

MISO 5

MISO 4

MISO 3

MISO 2

MISO 1

MISO 0

MOSI

STAR

0 (read)

MISO

ERR

ACK=ER

BATFA

LxWU WILS CANW

Test/

def

VMONF SPIerr

CANF

MOSI

STAR

1 (write)

ERR_EXT

CAN SR1

CAN SR0

CAN WU - pattern

CRANK

MISO

ERR

ACK=ER

PASS ID1

PASS ID0

MET ID1

MET ID0

MOSI

STAR

MISO

ERR

ACK=ER

Bus

dom

VDD

temp

Rx-PR CAN cur Tx-PD VSO

CANF2 VSUV CANF1 VIO low CANF0 VDDlo

BATFAIL

Description

VSUP voltage < VSUP low threshold, also called Power On flag

Set

VSUP below VBFTH (3.3 V)

Reset

Entering Normal mode or P_SPI reading (Listen Only)

Action

Avoid entering Go To Sleep. Set

ERR low in Listen Only mode coming from low power modes

33902 Datasheet(PDF) 22 Page - Freescale Semiconductor, Inc

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