UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
292 of 1269
NXP Semiconductors
UM10503
Chapter 15: LPC43xx System Control Unit (SCU)/ IO configuration
15.4.2 Pin configuration registers for high-drive pins
Each digital pin and each clock pin on the LPC43xx have an associated pin configuration
register which determines the pin’s function and electrical characteristics. The assigned
functions for each pin are listed in <tbd>.
The pin configuration registers for high-drive pins control the following pins:
•
P1_17
•
P2_3 to P2_5
Table 133. Pin configuration registers for normal-drive pins (SFS, address 0x4008 6000
(SPSP0_0) to 0x4008 67AC (SFSPF_11)) bit description
Bit
Symbol
Value
Description
Reset
value
Access
2:0
MODE
Select pin function.
0
R/W
0x0
Function 0 (default)
0x1
Function 1
0x2
Function 2
0x3
Function 3
0x4
Function 4
0x5
Function 5
0x6
Function 6
0x7
Function 7
3
EPD
Enable pull-down resistor at pad.
0
R/W
0
Disable pull-down.
1
Enable pull-down.Enable both pull-down
resistor and pull-up resistor for repeater
mode.
4
EPUN
Disable pull-up resistor at pad. By default,
the pull-up resistor is enabled at reset.
0
R/W
0
Enable pull-up. Enable both pull-down
resistor and pull-up resistor for repeater
mode.
1
Disable pull-up.
5
EHS
Select Slew rate.
0
R/W
0
Slow (low noise with medium speed)
1
Fast (medium noise with fast speed)
6
EZI
Input buffer enable. The input buffer is
disabled by default at reset and must be
enabled for receiving.
0
R/W
0
Disable input buffer
1
Enable input buffer
7
ZIF
Input glitch filter. Disable the input glitch filter
for clocking signals higher than 30 MHz.
0
R/W
0
Enable input glitch filter
1
Disable input glitch filter
31:8
-
Reserved
-
-