33905 datasheet(52/91 Pages) FREESCALE

Part #	33905

Description	System Basis Chip Gen2 with High Speed CAN and LIN Interface

PDF	91 Pages

Scroll/Zoom	100%

Manufacturer	FREESCALE [Freescale Semiconductor, Inc]

Direct Link	http://www.freescale.com

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52 / 91 page

Analog Integrated Circuit Device Data

Freescale Semiconductor

33904/5

CAN INTERFACE

CAN BUS FAULT DIAGNOSTIC

TXD TO RXD SHORT CIRCUIT:

Principle

In case TXD is shorted to RXD during incoming dominant

information, RXD is set low. Consequently, the TXD pin is low

and drives CANH and CANL into a dominant state. Thus the

bus is stuck in dominant. No further communication is

possible.

Detection and Recovery

The TXD permanent dominant timeout will be activated and

release the CANL and CANH drivers. However, at the next

incoming dominant bit, the bus will then be stuck in dominant

again. The recovery condition is same as the TXD dominant

failure

IMPORTANT INFORMATION FOR BUS DRIVER

REACTIVATION

The driver stays disabled until the failure is/are removed

(Tx and/or RX is no longer permanent dominant or recessive

state or shorted) and the failure flags cleared (read). The CAN

driver must be set by SPI in TxRx mode in order to re enable

the CAN bus driver.

33905 Datasheet(PDF) 52 Page - Freescale Semiconductor, Inc