RM0312 datasheet(75/275 Pages) STMICROELECTRONICS

75 / 275 page

DocID022352 Rev 3

75/275

RM0312

General purpose I/O ports (GPIO)

10.1

Introduction

General purpose input/output ports are used for data transfers between the chip and the

external world. An I/O port can contain up to eight pins. Each pin can be individually

programmed as a digital input or digital output. In addition, some ports may have alternate

functions like analog inputs, external interrupts, input/output for on-chip peripherals. Only

one alternate function can be mapped to a pin at a time.

An output data register, input data register, data direction register and two configuration

registers are associated with each port. A particular port will behave as an input or output

depending on the status of the data direction register of the port.

10.2

GPIO main features

•

Port bits can be configured individually

•

Selectable input modes: floating input or input with pull-up

•

Selectable output modes: push-pull output or pseudo-open-drain.

•

Separate registers for data input and output

•

External interrupts can be enabled and disabled individually

•

Output slope control for reduced EMC noise

•

Alternate function I/Os for on-chip peripherals

•

Read-modify-write possible on data output latch

•

I/O state guaranteed in voltage range 1.6 V to VDDIOmax

RM0312 数据表(PDF) 75 Page - STMicroelectronics