RM0082
BS_General purpose input/output (GPIO)
Doc ID 018672 Rev 1
325/844
18
BS_General purpose input/output (GPIO)
18.1 Overview
Within its Basic Subsystem, SPEAr300 provides a
General Purpose Input/Output (GPIO)
providing 6 programmable inputs or outputs. Each input/output can be controlled through an
APB interface.
Main features of the GPIO are:
●
Six individually programmable input/output pins (default to input at reset)
●
2x GPIO dedicated for SPI chip select
●
An APB slave acting as control interface
●
Programmable interrupt generation capability on any number of pins.
●
Bit masking in both read and write operation through address lines.
18.2 Functional
description
18.2.1 Block
diagram
shows the block diagram of GPIO.
Figure 29.
GPIO block diagram
18.2.2 Signal
interfaces
The GPIO directly interfaces with the signals summarized in
. A functional diagram of these signal interfaces is given in
.
Interrupt Detection
logic
Input/
Output
Multiplexor
Input Data
Enable lines
Output Data
AMBA APB Interface
Table 263.
GPIO signal interface
Group
Signal name
Direction
Size
(bit)
Description
External
(to chip pads)
nGPEN
Output
6
Output pad enable signal (active low).
GPOUT
Output
6
Output pad data signal driver.
GPIN
Input
6
Input data from chip pad.