CAN Control Registers
1564
SPRUH22I – April 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
M3 Controller Area Network (CAN)
Table 23-24. IF3 Arbitration Register Field Descriptions
Bit
Field
Value
Description
31
MsgVal
Message Valid
0
The message object is ignored by the message handler.
1
The message object is to be used by the message handler.
The CPU should reset the MsgVal bit of all unused Messages Objects during the initialization
before it resets bit Init in the CAN Control Register. This bit must also be reset before the identifier
ID[28:0], the control bits Xtd, Dir or DLC[3:0] are modified, or if the messages object is no longer
required.
30
Xtd
Extended Identifier
0
The 11-bit ("standard") Identifier is used for this message object.
1
The 29-bit ("extended") Identifier is used for this message object.
29
Dir
Message Direction
0
Direction = receive: On TxRqst, a remote frame with the identifier of this message object is
transmitted. On reception of a data frame with matching identifier, that message is stored in this
message object.
1
Direction = transmit: On TxRqst, the respective message object is transmitted as a data frame. On
reception of a remote frame with matching identifier, the TxRqst bit of this message object is set (if
RmtEn = one).
28-0
ID[28:0]
Message Identifier
ID[28:0] 29-bit Identifier ("Extended Frame")
ID[28:1
8]
11-bit Identifier ("Standard Frame")
23.15.22 IF3 Message Control Register (CAN IF3MCTL)
The IF3 Message Control register (CAN IF3MCTL) is shown and described in the figure and table below.
Figure 23-47. IF3 Message Control Register (CAN IF3MCTL) [offset = 0x14C]
31
16
Reserved
R-0
15
14
13
12
11
10
9
8
7
6
4
3
0
New
Dat
Msg
Lst
Int
Pnd
UMask
TxIE
RxIE
Rmt
En
Tx
Rqst
EoB
Reserved
DLC[3:0]
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
LEGEND: R = Read; -
n
= value after reset
Table 23-25. IF3 Message Control Register Field Descriptions
Bit
Field
Value
Description
31-16
Reserved
Reserved
15
NewDat
New Data
0
No new data has been written into the data portion of this message object by the message handler
since the last time when this flag was cleared by the CPU.
1
The message handler or the CPU has written new data into the data portion of this message object.
14
MsgLst
Message Lost (only valid for message objects with direction = receive)
0
No message lost since the last time when this bit was reset by the CPU.
1
The message handler stored a new message into this object when NewDat was still set, so the
previous message has been overwritten.
13
IntPnd
Interrupt Pending
0
This message object is not the source of an interrupt.
1
This message object is the source of an interrupt. The Interrupt Identifier in the Interrupt Register
will point to this message object if there is no other interrupt source with higher priority.