MINI55LDE Datasheet, PDF (46/74 Pages) List of Unclassifed Manufacturers – 32-bit Microcontroller

Mini55
6.5 General Purpose I/O (GPIO)
6.5.1 Overview
The NuMicro^® Mini55 series has up to 33 General Purpose I/O pins to be shared with other
function pins depending on the chip configuration. These 33 pins are arranged in 6 ports named
as P0, P1, P2, P3, P4 and P5. Each of the 33 pins is independent and has the corresponding
register bits to control the pin mode function and data.
The I/O type of each pin can be configured by software individually as Input, Push-pull output,
Open-drain output, or Quasi-bidirectional mode. After the chip is reset, the I/O mode of all pins is
stay in input mode and each port data register Px_DOUT[n] resets to 1. For Quasi-bidirectional
mode, each I/O pin is equipped with a very weak individual pull-up resistor about 110 k ~ 300
k for V_DD is from 5.0 V to 2.1 V.
6.5.2 Features
 Four I/O modes:
 Quasi-bidirectional mode
 Push-pull output
 Open-drain output
 Input-only with high impendence
 Quasi-bidirectional TTL/Schmitt trigger input mode selected by SYS_Px_MFP[23:16]
 I/O pin configured as interrupt source with edge/level setting
 I/O pin internal pull-up resistor enabled only in Quasi-bidirectional I/O mode
 Enabling the pin interrupt function will also enable the pin wake-up function
 High driver and high sink I/O mode support
 Configurable default I/O mode of all pins after reset by CIOINI (Config0[10]) setting
 CIOINI = 0, all GPIO pins in Quasi-bidirectional mode after chip reset
 CIOINI = 1, all GPIO pins in Input tri-state mode after chip reset
Apr 18, 2017
Page 46 of 74
Rev.1.00