Datasheet

97
A/T89C51CC01
4129N–CAN–03/08
Table 59. CANGSTA Register
CANGSTA (S:AAh Read Only)
CAN General Status Register
Reset Value = x0x0 0000b
7 6 5 4 3 2 1 0
- 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.
6 OVFG
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.
4 TBSY
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.
2 ENFG
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.
1 BOFF
Bus Off Mode
see Figure 49
0 ERRP
Error Passive Mode
see Figure 49