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CHAPTER 23 CAN CONTROLLER
23.6.2
Bus Operation Stop Bit (HALT = 1)
The bus operation stop bit sets or cancels stopping of bus operation, or indicates its
status.
■ Conditions for Setting Bus Operation Stop (HALT=1)
There are three conditions for setting bus operation stop (HALT = 1):
• After hardware reset
• When node status changed to bus off
• By writing "1" to HALT
Notes:
• The bus operation should be stopped by writing "1" to HALT before the F
low-power consumption mode (stop mode and time-base timer mode).
If transmission is in progress when "1" is written to HALT, the bus operation is stopped (HALT =
1) after transmission is terminated. If reception is in progress when "1" is written to HALT, the bus
operation is stopped immediately (HALT = 1). If received messages are being stored in the
message buffer (x), stop the bus operation (HALT = 1) after storing the messages.
• To check whether the bus operation has stopped, always read the HALT bit.
■ Conditions for Canceling Bus Operation Stop (HALT = 0)
By writing "0" to HALT
Notes:
• Canceling the bus operation stop after hardware reset or by writing "1" to HALT as above
conditions is performed after "0" is written to HALT and continuous 11-bit "H" levels (recessive
bits) have been input to the receive input pin (RX) (HALT = 0).
• Canceling the bus operation stop when the node status is changed to bus off as above conditions
is performed after "0" is written to HALT and continuous 11-bit "H" levels (recessive bits) have
been input 128 times to the receive input pin (RX) (HALT = 0). Then, the values of both transmit
and receive error counters reach "0" and the node status is changed to error active.
• When write "0" to HALT during the node status is Bus Off, ensure that "1" is written to this bit.
472
2
MC-16LX is changed in
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