EKE-Electronics CVB1621A Technical Manual page 35

The Bus state
It is a status register of the SJA1000 CAN controller (a hexadecimal value). The bit
fields of the bus state are explained in the table below:
Table 5.2: Bus state addresses and contents of input ports
Bit Name
7 Bus status
6 Error status
5 Transmit
status
4 Receive
status
3 Transmit
complete
status
2 Transmit
buffer status
1 Data overrun
status
0 Receive buffer
status
Rx errors
RX error counter register of the SJA1000 controller. It reflects the current value of
the receive error counter. A hexadecimal value.
Tx errors
TX error counter register of the SJA1000 controller. It reflects the current value of
the transmit error counter. A hexadecimal value.
CVB1621A and CVB2456A Technical Manual, ver. 3.00
Value Function
1 bus-off; the CAN controller is not involved in bus
activities
0 bus-on; the CAN controller is involved in bus activities
1 error; at least one of the error counters has reached or
exceeded the warning limit
0 ok; both error counters are below the warning limit
1 transmit; the CAN controller is transmitting a message
0 idle
1 receive; the CAN controller is receiving a message
0 idle
1 complete; last requested transmission has been
successfully completed
0 incomplete; previously requested transmission is not yet
completed
1 released; the CPU may write a message into the
transmit buffer
0 locked; the CPU cannot access the transmit buffer; a
message is either waiting for transmission or is in the
process of being
1 overrun; a message was lost because there was not
enough space for that message in the RXFIFO
0 absent; no data overrun has occurred since the last
clear data overrun command was given
1 full; one or more complete messages are available in the
RXFIFO
0 empty; no message is available
Command line interface
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