Datasheet

107
AT89C51CC03
4182O–CAN–09/08
Table 49. CANGSTA Register
CANGSTA (S:AAh Read Only)
CAN General Status Register
Reset Value = x0x0 0000b
76543210
- OVFG - TBSY RBSY ENFG BOFF ERRP
Bit
Number Bit Mnemonic Description
7-
Reserved
The values read from this bit is indeterminate. Do not set this bit.
6OVFG
Overload Frame Flag
This status bit is set by the hardware as long as the produced overload frame
is sent.
This flag does not generate an interrupt
5-
Reserved
The values read from this bit is indeterminate. Do not set this bit.
4TBSY
Transmitter Busy
This status bit is set by the hardware as long as the CAN transmitter
generates a frame (remote, data, overload or error frame) or an ack field. This
bit is also active during an InterFrame Spacing if a frame must be sent.
This flag does not generate an interrupt.
3 RBSY
Receiver Busy
This status bit is set by the hardware as long as the CAN receiver acquires or
monitors a frame.
This flag does not generate an interrupt.
2ENFG
Enable On-chip CAN Controller Flag
Because an enable/disable command is not effective immediately, this status
bit gives the true state of a chosen mode.
This flag does not generate an interrupt.
1BOFF
Bus Off Mode
see Figure 53
0 ERRP
Error Passive Mode
see Figure 53