DR
AFT
DR
AFT
DRAFT
DR
D
RAFT
DRAFT
DRA
FT DRAF
D
RAFT DRAFT DRAFT DRAFT DRAFT D
DRAFT
D
RAFT DRA
FT DRAFT DRAFT DRAFT DRA
UM10316_0
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 00.06 — 17 December 2008
334 of 571
NXP Semiconductors
UM10316
Chapter 21: LPC29xx CAN 0/1
9.13 CAN controller transmit-buffer message info registers
The CAN controller transmit-buffer message info registers CCTXB1MI, CCTXB2MI and
CCTXB3MI each reflect the characteristics of the transmit message. These registers are
only writable when the transmit buffer is released (i.e. corresponding transmit-buffer
status bit is logic 1).
shows the bit assignment of the CCTXB1MI, CCTXB2MI and CCTXB3MI
registers.
Table 279. CAN controller receive-buffer data B register bit description (CCRXBDB, address
0xE008 002C (CAN0) and 0xE008 102C (CAN1))
* = reset value
Bit
Symbol
Access
Value
Description
31 to 24 DB8[7:0]
R
Data byte 8. If the data-length code value is
eight or more this register contains the eighth
data byte of the received message
00h*
23 to 16 DB7[7:0]
R
Data byte 7. If the data-length code value is
seven or more this register contains the
seventh data byte of the received message
00h*
15 to 8
DB6[7:0]
R
Data byte 6. If the data-length code value is six
or more this register contains the sixth data
byte of the received message
00h*
7 to 0
DB5[7:0]
R
Data byte 5. If the data-length code value is five
or more this register contains the fifth data byte
of the received message
00h*
Table 280. CAN controller transmit-buffer message info register bit description
(CCTXB1/2/3MI, addresses 0xE008 0030, 0xE008 0040, 0xE008 0050 (CAN0), and
0xE008 1030, 0xE008 1040, 0xE008 1050 (CAN1))
* = reset value
Bit
Symbol
Access
Value
Description
31
FF
R/W
Frame format
1
An extended frame-format message is
transmitted
0*
A standard frame-format message is
transmitted
30
RTR
R/W
Remote frame request
1
A remote frame-format message is transmitted
0*
A data frame-format message is transmitted
29 to 20 reserved
R
-
Reserved; do not modify. Read as logic 0