Functional Operation
9-22
ADSP-BF537 Blackfin Processor Hardware Reference
If a mailbox is configured as “transmit” (
MDn
=
0
) and
TDA
is set, the con-
tent of the data field of that mailbox can be updated. If there is an
incoming remote request frame while the mailbox is temporarily disabled,
the corresponding transmit request set bit (
TRSn
) is set by the internal
logic and the data length code of the incoming message is written to the
corresponding mailbox. However, the message being requested is not sent
until the temporary disable request is cleared (
TDR
=
0
). Similarly, all trans-
mit requests for temporarily disabled mailboxes are ignored until
TDR
is
cleared. Additionally, transmission of a message is immediately aborted if
the mailbox is temporarily disabled and the corresponding
TRRn
bit for
this mailbox is set.
If a mailbox is configured as “receive” (
MDn
=
1
), the temporary disable flag
is set and the mailbox is not processed. If there is an incoming message for
the mailbox n being temporarily disabled, the internal logic waits until the
reception is complete or there is an error on the CAN bus to set
TDA
. Once
TDA
is set, the mailbox can then be completely disabled (
MCn
=
0
) without
the risk of losing an incoming frame. The temporary disable request (
TDR
)
bit must then be reset as soon as possible.
When
TDA
is set for a given mailbox, only the data field of that mailbox
can be updated. Accesses to the control bits and the identifier are denied.
Functional Operation
The following sections describe the functional operation of the CAN
module, including interrupts, the event counter, warnings and errors,
debug features, and low power features.
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 ...