ADSP-BF50x Blackfin Processor Hardware Reference
17-9
CAN Module
Due to the inherent nature of the CAN protocol, a dominant bit in
the
RTR
field wins arbitration against a remote frame request
(
RTR
=
1
) for the same message ID, thereby defining a remote request
to be lower priority than a data frame.
The next field of interest is the
IDE
. When set, it indicates that the mes-
sage is an extended frame with a 29-bit identifier instead of an 11-bit
identifier. In an extended frame, the first part of the message resembles
Figure 17-6
.
As could be concluded with regards to the
RTR
field, a dominant bit in the
IDE
field wins arbitration against an extended frame with the same lower
11-bits, therefore, standard frames are higher priority than extended
frames. The substitute remote request bit (
SRR
, always sent as recessive),
the reserved bits
r0
and
r1
(always sent as dominant), and the checksum
(
CRC
) are generated automatically by the internal logic.
CAN Operation
The CAN controller is in configuration mode when coming out of proces-
sor reset or hibernate. It is only when the CAN is in configuration mode
that hardware behavior can be altered. Before initializing the mailboxes
themselves, the CAN bit timing must be set up to work on the CAN bus
that the controller is expected to connect to.
Figure 17-6. Extended CAN Frame
SOF
IDENTIFIER
SRR
1
11
1
1
18
1
1
4
RTR
IDE
r1
1
IDENTIFIER
r0
DLC
Содержание EZ-KIT Lite ADSP-BF506F
Страница 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 132: ...Unique Information for the ADSP BF50x Processor 4 22 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 342: ...Unique Information for the ADSP BF50x Processor 7 106 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 484: ...Unique Information for the ADSP BF50x Processor 10 60 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 493: ...ADSP BF50x Blackfin Processor Hardware Reference 11 9 Core Timer Unique Information for the ADSP BF50x Processor None ...
Страница 494: ...Unique Information for the ADSP BF50x Processor 11 10 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 506: ...Unique Information for the ADSP BF50x Processor 12 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 544: ...Unique Information for the ADSP BF50x Processor 13 38 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 712: ...Unique Information for the ADSP BF50x Processor 16 62 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 972: ...Unique Information for the ADSP BF50x Processor 20 38 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...