uja1061 NXP Semiconductors, uja1061 Datasheet - Page 20

• Manufacturer Part Number: uja1061
• Description: Low Speed Can/lin System Basis Chip
• Manufacturer: NXP Semiconductors

NXP Semiconductors
UJA1061_5
Product data sheet
6.7.1.1 Active mode
6.7.1.2 On-line mode
6.7.1.3 On-line Listen mode
6.7.1.4 Off-line mode
6.7.2 CAN wake-up
In the System Diagnosis register two dedicated CAN status bits (CANMD) are available to
signal the mode of the transceiver.
In Active mode the CAN transceiver can transmit data to and receive data from the CAN
bus. To enter Active mode the CMC bit must be set in the Physical Layer Control register
and the SBC must be in Normal mode or Flash mode. In Active mode voltage regulator V2
is activated automatically.
The CTC bit can be used to set the CAN transceiver to a Listen-only mode. The
transmitter output stage is disabled in this mode.
After an overload condition on voltage regulator V2, the CTC bit must be cleared for
reactivating the CAN transmitter.
When leaving Active mode the CAN transmitter is disabled and the CAN receiver is
monitoring the CAN-bus for a valid wake-up. The CAN termination is then working
autonomously.
In On-line mode the CAN bus pins and RTL and RTH pins are biased to the normal levels.
The CAN transmitter is deactivated and RXDC reflects the CAN wake-up status. A CAN
wake-up event is signalled to the microcontroller by setting pin RXDC to LOW.
If the bus stays continuously dominant or recessive for the Off-line time (t
Off-line state will be entered.
On-line Listen mode behaves similar to On-line mode, but all activity on the CAN-bus, with
exception of a special global wake-up request, is ignored. The global wake-up request is
described in
Off-line mode is the low power mode of the CAN transceiver. The CAN transceiver is
disabled to save supply current and is high-ohmic terminated to ground.
The CAN off-line time is programmable in two steps with the CAN Off-line Timer Control
(COTC) bit. When entering On-line (Listen) mode from Off-line mode the CAN off-line time
is temporarily extended to t
To wake-up the UJA1061 via CAN it has to be distinguished between a conventional
wake-up and a global wake-up in case partial networking is enabled (bit CPNC = 1).
To pass the wake-up filter for a conventional wake-up a dominant, recessive, dominant
signal on the CAN-bus is needed.
For a global wake-up out of On-line Listen mode two distinct CAN data patterns are
required (shown in hexadecimal code here):
•
•
In the Initial message: C6EE EEEE EEEE EEEF
In the Global wake-up message: C6EE EEEE EEEE EE37
Section
Rev. 05 — 22 November 2007
6.7.2. Pin RXDC is kept HIGH.
off-line(ext)
.
Fault-tolerant CAN/LIN fail-safe system basis chip
© NXP B.V. 2007 Nov 23. All rights reserved.
UJA1061
off-line
), the
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