MCZ33905BD3EK Freescale Semiconductor, MCZ33905BD3EK Datasheet - Page 54

• Manufacturer Part Number: MCZ33905BD3EK
• Description: 3.3V SBC HSCAN DUAL LIN
• Manufacturer: Freescale Semiconductor
• Series: -r

Specifications of MCZ33905BD3EK

• Main Purpose: Power Management, System Interface
• Embedded: No
• Utilized Ic / Part: MCZ33905
• Primary Attributes: CAN Transceiver, Dual LIN
• Secondary Attributes: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Recovery Condition
level at TXD as shown in the following illustration.
TXD PERMANENT DOMINANT
Principle
set into dominant level, and no communication is possible.
The device has a TXD permanent timeout detector. After the
timeout, the bus driver is disabled and the bus is released into
a recessive state. The TXD permanent flag is set.
Recovery
in case of a TXD short to RXD. The recovery condition for a
TXD permanent dominant (recovery means the re-activation
of the CAN drivers) is done by entering into a Normal mode
controlled by the MCU or when TXD is recessive while RXD
change from recessive to dominant.
TXD TO RXD SHORT-CIRCUIT:
Principle
information, RXD is set low. Consequently, the TXD pin is low
54
33903/4/5
CAN INTERFACE
CAN BUS FAULT DIAGNOSTIC
If the TXD is set to a permanent low level, the CAN bus is
The TXD permanent dominant is used and activated also
The internal recovery is done by sampling a correct low
In case TXD is shorted to RXD during incoming dominant
CANL&H
RXD output
Diff output
RxD flag
Figure 37. RxD Path Simplified Schematic, RxD Short to V
RxD flag latched
RxD short to V DD
The RxD flag is not the RXPR bit in the LPC register, and neither is the CANF in the INTR register.
Sampling
RxD no longer shorted to V DD
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
(TxD and/or RxD 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 TxD/RxD mode
in order to re enable the CAN bus driver.
The driver stays disabled until the failure is/are removed
Sampling
DD
Analog Integrated Circuit Device Data
Detection
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