DCAN Registers
23.4.56 RIOC Register (offset = 1E4h) [reset = 0h]
RIOC is shown in
and described in
The CAN_RX pin of the DCAN module can be used as general purpose IO pin if CAN function is not
needed. The values of the IO control registers are writable only if Init bit of CAN control register is set. The
OD, Func and Dir bits of the CAN RX IO control register are forced to certain values when the Init bit of
CAN control register is reset (see bit descriptions).
Figure 23-74. RIOC Register
31
30
29
28
27
26
25
24
Reserved
R-0h
23
22
21
20
19
18
17
16
Reserved
PU
PD
OD
R-0h
R/W-0h
R/W-0h
R/WP-0h
15
14
13
12
11
10
9
8
Reserved
R-0h
7
6
5
4
3
2
1
0
Reserved
Func
Dir
Out
In
R-0h
R/WP-0h
R/WP-0h
R/WP-0h
R-0h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 23-69. RIOC Register Field Descriptions
Bit
Field
Type
Reset
Description
31-19
Reserved
R
0h
18
PU
R/W
0h
CAN_RX pull up/pull down select.
This bit is only active when CAN_RX is configured to be an input.
0x0 = CAN_RX pull down is selected, when pull logic is active (PD =
0).
0x1 = CAN_T=RX pull up is selected, when pull logic is active(PD =
0).
17
PD
R/W
0h
CAN_RX pull disable.
This bit is only active when CAN_TX is configured to be an input.
0x0 = CAN_RX pull is active
0x1 = CAN_RX pull is disabled
16
OD
R/WP
0h
CAN_RX open drain enable.
This bit is only active when CAN_RX is configured to be in GIO
mode (TIOC.Func=0).
Forced to '0' if Init bit of CAN control register is reset.
0x0 = The CAN_RX pin is configured in push/pull mode.
0x1 = The CAN_RX pin is configured in open drain mode.
15-4
Reserved
R
0h
3
Func
R/WP
0h
CAN_RX function.
This bit changes the function of the CAN_RX pin.
Forced to '1' if Init bit of CAN control register is reset.
0x0 = CAN_RX pin is in GIO mode.
0x1 = CAN_RX pin is in functional mode (as an output to transmit
CAN data).
2
Dir
R/WP
0h
CAN_RX data direction.
This bit controls the direction of the CAN_RX pin when it is
configured to be in GIO mode only (TIOC.Func=0).
Forced to '1' if Init bit of CAN control register is reset.
0x0 = The CAN_RX pin is an input.
0x1 = The CAN_RX pin is an output
3991
SPRUH73H – October 2011 – Revised April 2013
Controller Area Network (CAN)
Copyright © 2011–2013, Texas Instruments Incorporated