If2 Arbitration Register (Can If2Arb) [Offset = 0X128]; If1 And If2 Arbitration Registers Field Descriptions - Texas Instruments Concerto F28M36 Series Technical Reference Manual

CAN Control Registers
Figure 23-37. IF2 Arbitration Register (CAN IF2ARB) [offset = 0x128]
31 30 29 28
MsgVa Xtd Dir
l
R/WP- R/WP- R/WP-
0 0 0
15
LEGEND: R = Read; WP = Protected Write (protected by Busy bit); -n = value after reset
Bit Field
31 MsgVal
30 Xtd
29 Dir
28-0 ID[28:0]
ID[28:0] 29-bit Identifier ("Extended Frame")
The Arbitration bits ID[28:0], Xtd, and Dir are used to define the identifier and type of outgoing messages
and (together with the Mask bits Msk[28:0], MXtd, and MDir) for acceptance filtering of incoming
messages.
A received message is stored into the valid message object with matching identifier and Direction =
receive (data frame) or Direction = transmit (remote frame).
Extended frames can be stored only in message objects with Xtd = one, standard frames in message
objects with Xtd = zero.
If a received message (data frame or remote frame) matches more than one valid message objects, it is
stored into the one with the lowest message number.
23.15.17 IF1 and IF2 Message Control Registers (CAN IF1MCTL, CAN IF2MCTL)
The bits of the IF1 and IF2 Message Control registers mirror the message control bits of a message
object. The function of the relevant message objects bits is described in
NOTE: While the Busy bit of the IF1 and IF2 Command Register is one, IF1 and IF2 register sets
are write protected.
1596
M3 Controller Area Network (CAN)
Table 23-20. IF1 and IF2 Arbitration Registers Field Descriptions
Value Description
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.
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.
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).
Message Identifier
ID[28:1 11-bit Identifier ("Standard Frame")
8]
Copyright © 2012–2019, Texas Instruments Incorporated
ID[28:16]
R/WP-0
ID[15:0]
R/WP-0
SPRUHE8E – October 2012 – Revised November 2019
www.ti.com
Section 23.14.1.
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