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Rainbow Electronics T89C51CC01 User Manual

Page 87

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87

T89C51CC01

Rev. D – 17-Dec-01

Table 39. CANGSTA Register

CANGSTA (S:AAh)
CAN General Status Register

Note:

1. These fields are Read Only.

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 (1)
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 (1)
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 (1)
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 (1)
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 (1)
see Figure 36

0

ERRP

Error passive mode (1)
see Figure 36