
UM10800
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© NXP Semiconductors N.V. 2016. All rights reserved.
User manual
Rev. 1.2 — 5 October 2016
89 of 487
8.1 How to read this chapter
The IOCON block is identical for all LPC82x parts. Registers for pins that are not available
on a specific package are reserved.
8.2 Features
The following electrical properties are configurable for each pin:
•
Pull-up/pull-down resistor
•
Open-drain mode
•
Hysteresis
•
Digital glitch filter with programmable time constant
•
Analog mode (for a subset of pins, see the LPC82x data sheet)
The true open-drain pins PIO0_10 and PIO0_11 can be configured for different I2C-bus
speeds.
8.3 Basic configuration
Enable the clock to the IOCON in the SYSAHBCLKCTRL register (
, bit 18). Once
the pins are configured, you can disable the IOCON clock to conserve power.
Remark:
If the open-drain pins PIO0_10 and PIO0_11 are not available on the package,
prevent the pins from internally floating as follows: Set bits 10 and 11 in the GPIO DIR0
register to 1 to enable the output driver and write 1 to bits 10 and 11 in the GPIO CLR0
register to drive the outputs LOW internally.
UM10800
Chapter 8: LPC82x I/O configuration (IOCON)
Rev. 1.2 — 5 October 2016
User manual
Table 80.
Pinout summary
Package
Pins/configuration registers available
TSSOP20
PIO0_0 to PIO0_5; PIO0_8 to PIO0_15; PIO0_17; PIO0_23
HVQFN33
PIO0_0 to PIO0_28