Datasheet

LPC81XM All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 4.3 — 22 April 2014 18 of 76
NXP Semiconductors
LPC81xM
32-bit ARM Cortex-M0+ microcontroller
• An entire port value can be written in one instruction.
• Mask, set, and clear operations are supported for the entire port.
All GPIO port pins are fixed-pin functions that are enabled or disabled on the pins by the
switch matrix. Therefore each GPIO port pin is assigned to one specific pin and cannot be
moved to another pin. Except for pins SWDIO/PIO0_2, SWCLK/PIO0_3, and
RESET
/PIO0_5, the switch matrix enables the GPIO port pin function by default.
8.10.1 Features
• Bit level port registers allow a single instruction to set and clear any number of bits in
one write operation.
• Direction control of individual bits.
• All I/O default to inputs with internal pull-up resistors enabled after reset - except for
the I
2
C-bus true open-drain pins PIO0_2 and PIO0_3.
• Pull-up/pull-down configuration, repeater, and open-drain modes can be programmed
through the IOCON block for each GPIO pin (see Figure 8
).
•
8.11 Pin interrupt/pattern match engine
The pin interrupt block configures up to eight pins from all digital pins for providing eight
external interrupts connected to the NVIC.
The pattern match engine can be used, in conjunction with software, to create complex
state machines based on pin inputs.
Any digital pin, independently of the function selected through the switch matrix, can be
configured through the SYSCON block as input to the pin interrupt or pattern match
engine. The registers that control the pin interrupt or pattern match engine are located on
the IO+ bus for fast single-cycle access.
8.11.1 Features
• Pin interrupts
– Up to eight pins can be selected from all digital pins as edge- or level-sensitive
interrupt requests. Each request creates a separate interrupt in the NVIC.
– Edge-sensitive interrupt pins can interrupt on rising or falling edges or both.
– Level-sensitive interrupt pins can be HIGH- or LOW-active.
– Pin interrupts can wake up the LPC81xM from sleep mode, deep-sleep mode, and
power-down mode.
• Pin interrupt pattern match engine
– Up to eight pins can be selected from all digital pins to contribute to a boolean
expression. The boolean expression consists of specified levels and/or transitions
on various combinations of these pins.
– Each minterm (product term) comprising the specified boolean expression can
generate its own, dedicated interrupt request.
– Any occurrence of a pattern match can be programmed to also generate an RXEV
notification to the ARM CPU. The RXEV signal can be connected to a pin.