Message RAM
1056
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Controller Area Network (DCAN) Module
23.5.2 Addressing Message Objects in RAM
The starting location of a particular message object in RAM is:
Message RAM base a (message object number) × 0x20.
This means that Message Object 1 starts at offset 0x0020; Message Object 2 starts at offset 0x0040, and
so on.
NOTE:
0 is not a valid message object number. At address 0x0000, message object number 64 is
located. Writing to the address of an unimplemented message object may overwrite an
implemented message object.
The base address for DCAN1 RAM is FF1E 0000h, for DCAN2 RAM is FF1C 0000h, and for
DCAN3 RAM is FF1A 0000h.
Message Object number 1 has the highest priority.
Table 23-3. Message RAM Addressing in Debug/Suspend and RDA Mode
Message
Object
Number
Base Address Offset
Word
Number
Debug/Suspend mode,
see
RDA mode,
see
1
0x0020
1
Parity
Data Bytes 4-7
0x0024
2
MXtd, MDir, Mask
Data Bytes 0-3
0x0028
3
Xtd, Dir, ID
ID[27:0], DLC
0x002C
4
Ctrl
Mask, Xtd, Dir, ID[28]
0x0030
5
Data Bytes 3-0
Parity, Ctrl, MXtd, MDir
0x0034
6
Data Bytes 7-4
--
:
:
:
:
:
31
0x03E0
1
Parity
Data Bytes 4-7
0x03E4
2
MXtd, MDir, Mask
Data Bytes 0-3
0x03E8
3
Xtd, Dir, ID
ID[27]:0, DLC
0x03EC
4
Ctrl
Mask, Xtd, Dir, ID[28]
0x03F0
5
Data Bytes 3-0
Parity, Ctrl, MXtd, MDir
0x03F4
6
Data Bytes 7-4
--
:
:
:
:
:
63
0x07E0
1
Parity
Data Bytes 4-7
0x07E4
2
MXtd, MDir, Mask
Data Bytes 0-3
0x07E8
3
Xtd, Dir, ID
ID[27:0], DLC
0x07EC
4
Ctrl
Mask, Xtd, Dir, ID[28]
0x07F0
5
Data Bytes 3-0
Parity, Ctrl, MXtd, MDir
0x07F4
6
Data Bytes 7-4
--
64
0x0000
1
Parity
Data Bytes 4-7
0x0004
2
MXtd, MDir, Mask
Data Bytes 0-3
0x0008
3
Xtd, Dir, ID
ID[27]:0, DLC
0x000C
4
Ctrl
Mask, Xtd, Dir, ID[28]
0x0010
5
Data Bytes 3-0
Parity, Ctrl, MXtd, MDir
0x0014
6
Data Bytes 7-4
--