Analog Devices Blackfin ADSP-BF537 Hardware Reference Manual page 547

The mode auto acknowledge bit (
its own acknowledge during the ACK slot of the CAN frame. No external
devices or connections are necessary to read back a transmit message. In
this mode, the message that is sent is automatically stored in the internal
receive buffer. In auto acknowledge mode, the module itself transmits the
acknowledge. This acknowledge can be programmed to appear on the
pin if
CANTX DIL=1
internally, then these test mode bits should be set to
The disable internal loop bit (
output to be routed back to the receive input.
The disable transmit output bit (
pin. When this bit is set, the
The disable receive input bit (
When set, the internal logic receives recessive bits or receives the internally
generated transmit value in the case of the internal loop enabled (
In either case, the value on the
The disable error counters bit (
receive error counters in the
holds its current contents and is not allowed to increment or dec-
CAN_CEC
rement the error counters. This mode does not conform to the CAN
specification.
Writes to the error counters should be in debug mode only. Write
access during reception may lead to undefined values. The maxi-
mum value which can be written into the error counters is 255.
Thus, the error counter value of 256 which forces the module into
the bus off state can not be written into the error counters.
Table 9-4 shows several common combinations of test mode bits.
ADSP-BF537 Blackfin Processor Hardware Reference
) allows the CAN module to generate
MAA
and . If the acknowledge is only going to be used
DTO=0
) is used to internally enable the transmit
DIL
) is used to disable the
DTO
pin continuously drives recessive bits.
CANTX
) is used to disable the
DRI
CANRX
) is used to disable the transmit and
DEC
CAN_CEC
DIL=0
input pin is ignored.
register. When this bit is set, the
CAN Module
and .
DTO=1
output
CANTX
input.
CANRX
).
DIL=0
9-35