CAN Operation
9-16
ADSP-BF537 Blackfin Processor Hardware Reference
Each incoming data frame is compared to all identifiers stored in active
receive mailboxes (
MDn
=
1
and
MCn
=
1
) and to all active transmit mail-
boxes with the remote frame handling feature enabled (
RFHn
=
1
in
CAN_RFHx
).
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. 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 9-1. 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 Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...