mc33742 Freescale Semiconductor, Inc, mc33742 Datasheet - Page 36

• Manufacturer Part Number: mc33742
• Description: Mc33742 System Basis Chip Sbc With Enhanced High-speed Can Transceiver
• Manufacturer: Freescale Semiconductor, Inc

CAN IN SLEEP MODE WITH WAKE-UP ENABLE
enable, the CAN bus traffic is detected. The CAN bus wake-
up is a pattern wake-up.
PATTERN WAKE-UP
must be fulfilled:
• The CAN interface wake-up receiver must receive a series
36
2.5 V
33742
FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
2.5 V
When the CAN interface is in Sleep mode with wake-up
In order to wake up the CAN interface, the following criteria
of three consecutive valid dominant pulses, each of which
must be longer than 500 ns and shorter than 500 µs.
TXD
CANH
CANL
RXD
TXD
CANH
CANL
RXD
CANL Dominant
CANH Dominant
CAN in TXRX Mode
CANH Dominant
CANL Dominant
Figure 22. CAN Bus Signal During Can Sleep State and Wake-Up Sequence
CAN in TXRX Mode
CANL/CANH Recessive
CANL/CANH Recessive
Figure 21. CAN Signals in TXRX and Sleep Modes
CAN Bus Sleep State
Ground
WU Receiver
CAN in Sleep Mode (Wake-Up Enable)
CANL Dominant
CANH Dominant
• The distance between 2 pulses must be lower than 500 µs.
• The three pulses must occur within a time frame of 1.0 ms.
wake-up by any CAN message content.
bus Sleep state and wake-up sequence.
(Wake-Up Enable or Disable)
Min 500 ns
Max 500 µs
The pattern wake-up of the 33742 CAN interface allow
Figure 22
Pulse # 1
CAN in Sleep Mode
Ground
below illustrates the CAN signals during a CAN
Internal Wake-Up Signal
CANH Dominant
CANL Dominant
Incoming CAN Message
Pulse # 2
Analog Integrated Circuit Device Data
(Controlled by SPI Command)
Freescale Semiconductor
CAN in TXRX Mode
CANH Dominant
CANL Dominant
Pulse # 3