Texas Instruments TMS3320C5515 User Manual
Page 67
www.ti.com
System Configuration and Control
1.7.3.5
Pull-Up/Pull-Down Inhibit Register (PDINHIBR1, PDINHIBR2, and PDINHIBR3 [1C17h, 1C18h, and
1C19h]
The device allows you to individually enable or disable the internal pull-up and pull-down resistors. You
can individually inhibit the pull-up and pull-down resistors of the I/O pins through the pull-down/up inhibit
registers (PDINHIBRn). There is one pin, TRSTN, that has a pulldown that is permanently enabled and
cannot be disabled.
The pull-down inhibit register 1 (PDINHIBR1) is shown in
and described in
.
Figure 1-39. Pull-Down Inhibit Register 1 (PDINHIBR1) [1C17h]
15
14
13
12
11
10
9
8
Reserved
S15PD
S14PD
S13PD
S12PD
S11PD
S10PD
R-0
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
7
6
5
4
3
2
1
0
Reserved
S05PD
S04PD
S03PD
S02PD
S01PD
S00PD
R-0
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 1-49. Pull-Down Inhibit Register 1 (PDINHIBR1) Field Descriptions
Bit
Field
Value
Description
15-14
Reserved
0
Reserved.
13
S15PD
Serial port 1 pin 5 pull-down inhibit bit. Setting this bit to 1 disables the pin's internal pull-down.
0
Pin pull-down is enabled.
1
Pin pull-down is disabled.
12
S14PD
Serial port 1 pin 4 pull-down inhibit bit. Setting this bit to 1 disables the pin's internal pull-down.
0
Pin pull-down is enabled.
1
Pin pull-down is disabled.
11
S13PD
Serial port 1 pin 3 pull-down inhibit bit. Setting this bit to 1 disables the pin's internal pull-down.
0
Pin pull-down is enabled.
1
Pin pull-down is disabled.
10
S12PD
Serial port 1 pin 2 pull-down inhibit bit. Setting this bit to 1 disables the pin's internal pull-down.
0
Pin pull-down is enabled.
1
Pin pull-down is disabled.
9
S11PD
Serial port 1 pin 1 pull-down inhibit bit. Setting this bit to 1 disables the pin's internal pull-down.
0
Pin pull-down is enabled.
1
Pin pull-down is disabled.
8
S10PD
Serial port 1 pin 0 pull-down inhibit bit. Setting this bit to 1 disables the pin's internal pull-down.
0
Pin pull-down is enabled.
1
Pin pull-down is disabled.
7-6
Reserved
0
Reserved.
5
S05PD
Serial port 0 pin 5 pull-down inhibit bit. Setting this bit to 1 disables the pin's internal pull-down.
0
Pin pull-down is enabled.
1
Pin pull-down is disabled.
4
S04PD
Serial port 0 pin 4 pull-down inhibit bit. Setting this bit to 1 disables the pin's internal pull-down.
0
Pin pull-down is enabled.
1
Pin pull-down is disabled.
3
S03PD
Serial port 0 pin 3 pull-down inhibit bit. Setting this bit to 1 disables the pin's internal pull-down.
0
Pin pull-down is enabled.
1
Pin pull-down is disabled.
67
SPRUFX5A – October 2010 – Revised November 2010
System Control
Copyright © 2010, Texas Instruments Incorporated