UPD78F0890GK(A)-GAJ-AX NEC, UPD78F0890GK(A)-GAJ-AX Datasheet - Page 478

• Manufacturer Part Number: UPD78F0890GK(A)-GAJ-AX
• Description: 8BIT MCU, 128K FLASH, 7K RAM, LQFP
• Manufacturer: NEC

Specifications of UPD78F0890GK(A)-GAJ-AX

• Controller Family/series: UPD78F
• No. Of I/o's: 55
• Ram Memory Size: 7KB
• Cpu Speed: 20MHz
• No. Of Timers: 10
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 128KB
• Oscillator Type: External, Internal

16.13 Diagnosis Functions and Special Operational Modes
diagnosis functions or the operation of specific CAN communication methods.
16.13.1 Receive-only mode
can be used for CAN bus analysis nodes.
changed until "valid reception" is detected, so that the baud rates in the module match ("valid reception" means a
message frame has been received in the CAN protocol layer without occurrence of an error and with an appropriate
ACK between nodes connected to the CAN bus). A valid reception does not require message frames to be stored in a
receive message buffer (data frames) or transmit message buffer (remote frames). The event of valid reception is
indicated by setting the VALID bit of the C0CTRL register (1).
requests issued for message buffers defined as transmit message buffers are held pending.
Therefore, no active error flag can be transmitted from the CAN module to the CAN bus even when a CAN bus error is
detected while receiving a message frame.
transmission error counter TEC is never updated. Therefore, a CAN module in the receive-only mode does not enter
the bus-off state.
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The CAN module provides a receive-only mode, single-shot mode, and self-test mode to support CAN bus
The receive-only mode is used to monitor receive messages without causing any interference on the CAN bus and
For example, this mode can be used for automatic baud-rate detection. The baud rate in the CAN module is
In the receive-only mode, no message frames can be transmitted from the CAN module to the CAN bus. Transmit
In the receive-only mode, the CAN transmission pin (CTxD) in the CAN module is fixed to the recessive level.
Figure 16-33. CAN Module Terminal Connection in Receive-Only Mode
Fixed to
the recessive
level
CHAPTER 16 CAN CONTROLLER
CTxD
User’s Manual U17554EJ4V0UD
Since no transmission can be issued from the CAN module, the
Tx
CAN macro
CRxD
Rx