CP3BT23 Datasheet, PDF (115/260 Pages) Texas Instruments – CP3BT23 Reprogrammable Connectivity Processor with Bluetooth and Dual CAN Interfaces

18.10.3 Storage of Messages with Less Than 8 Data
Bytes
The data bytes that are not used for data transfer are “don’t
cares”. If the object is transmitted, the data within these
bytes will be ignored. If the object is received, the data with-
in these bytes will be overwritten with invalid data.
18.10.4 Storage of Extended Messages
If the IDE bit is set, the buffer handles extended frames. The
storage of the extended ID follows the descriptions in
Table 48. The SRR bit is at the bit position of the RTR bit for
standard frame and needs to be transmitted as 1.
Table 48 Extended Messages with 8 Data Bytes
Address
Buffer
Register
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0E F0XEh ID1
ID[28:18]
SRR IDE ID17:15]
0E F0XCh ID0
ID[14:0]
RTR
0E F0XAh DATA0
Data1[7:0]
Data2[7:0]
0E F0X8h
0E F0X6h
0E F0X4h
0E F0X2h
0E F0X0h
SRR
IDE
RTR
ID
DATA1
DATA2
DATA3
TSTP
CNSTAT
Data3[7:0]
Data4[7:0]
Data5[7:0]
Data6[7:0]
Data7[7:0]
Data8[7:0]
TSTP[15:0]
DLC
Reserved
PRI
ST
te ^{The Substitute Remote Request bit replaces}
the RTR bit used in standard frames at this bit
position. The SRR bit needs to be set by soft-
ware if the buffer is configured to transmit a
message with an extended identifier. It will be
le ^{received as monitored on the CAN bus.}
The Identifier Extension bit determines wheth-
er the message is a standard frame or an ex-
tended frame.
0 – Message is a standard frame using 11
identifier bits.
o _{1 – Message is an extended frame.}
The Remote Transmission Request bit indi-
cates whether the message is a data frame or
a remote frame.
s _{0 – Message is a data frame.}
1 – Message is a remote frame.
The ID field is used to build the 29-bit identifier
Ob ^{of an extended frame.}
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