CAN Operation
17-16
ADSP-BF50x Blackfin Processor Hardware Reference
The message identifier of the received message, along with the identifier
extension (
IDE
) and remote transmission request (
RTR
) bits, are compared
against each mailbox’s register settings. If the
AME
bit is not set, a match is
signalled only if
IDE
,
RTR
, and all identifier bits are exact. If, however,
AME
is set, the acceptance mask registers determine which of the identifier,
IDE
,
and
RTR
bits need to match. The logic applies
Received Message XNOR
CAN_IDx
or
AME AND CAN_AMx
. A one at the respective bit position in the
CAN_AMxx
mask registers means that the bit does not need to match when
AME = 1
. This way, a mailbox can accept a group of messages.
If the acceptance filter finds a matching identifier, the content of the
received data frame is stored in that mailbox. A received message is stored
only once, even if multiple receive mailboxes match its identifier. If the
current identifier does not match any mailbox, the message is not stored.
Table 17-1. Mailbox Used for Acceptance Mask Filtering
Mailbox Used for Acceptance Filtering
MCn
MDn RFHn Mailbox n
Comment
0
x
x
Ignored
Mailbox n disabled
1
0
0
Ignored
Mailbox n enabled
Mailbox n configured for transmit
Remote frame handling disabled
1
0
1
Used
Mailbox n enabled
Mailbox n configured for transmit
Remote frame handling enabled
1
1
x
Used
Mailbox n enabled
Mailbox n configured for receive
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...