SPRUGZ8D Datasheet, PDF (1115/3016 Pages) Texas Instruments – Technical Reference Manual

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Registers
5.14.1.20 IF1/IF2 Arbitration Registers (DCAN IF1ARB, DCAN IF2ARB)
The bits of the IF1/IF2 arbitration registers mirror the arbitration bits of a message object. The function of
the relevant message objects bits is described in Structure of Message Objects.
The IF1/IF2 arbitration registers (DCAN IF1ARB, DCAN IF2ARB) are shown in Figure 5-35 and Figure 5-
36 and described in Table 5-32.
NOTE: While Busy bit of IF1/IF2 command register is one, IF1/IF2 register set is write protected.
Figure 5-35. IF1 Arbitration Register (DCAN IF1ARB)
31
30
29
28
16
MsgVa Xtd Dir
l
ID[28:16]
R/WP- R/WP- R/WP-
0
0
0
R/WP-0
15
0
ID[15:0]
R/WP-0
LEGEND: R = Read only; WP = Write protected (protected by busy bit); -n = value after reset
Figure 5-36. IF2 Arbitration Register (DCAN IF2ARB)
31
30
29
28
16
MsgVa Xtd Dir
l
ID[28:16]
R/WP- R/WP- R/WP-
0
0
0
R/WP-0
15
0
ID[15:0]
R/WP-0
LEGEND: R = Read only; WP = Write protected (protected by busy bit); -n = value after reset
Table 5-32. IF1/IF2 Arbitration Registers (DCAN IF1ARB, DCAN IF2ARB) Field Descriptions
Bit Field
31 MsgVal
30 Xtd
29 Dir
Value
0
1
0
1
0
1
Description
Message valid
The message object is ignored by the message handler.
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
The 11-bit (“standard”) Identifier is used for this message object.
The 29-bit (“extended”) Identifier is used for this message object.
Message direction
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, this message is stored in this
message object.
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 = 1).
SPRUGZ8D – 14 November 2011 – Revised April 2013
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