6 user interface – Rainbow Electronics AT91CAP9S250A User Manual

Page 439

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439

6264A–CAP–21-May-07

AT91CAP9S500A/AT91CAP9S250A

• Four output signals on I/O lines 4 to 7 (to drive LEDs for example), driven high and low, no

pull-up resistor

• Four input signals on I/O lines 8 to 11 (to read push-button states for example), with pull-up

resistors, glitch filters and input change interrupts

• Four input signals on I/O line 12 to 15 to read an external device status (polled, thus no input

change interrupt), no pull-up resistor, no glitch filter

• I/O lines 16 to 19 assigned to peripheral A functions with pull-up resistor

• I/O lines 20 to 23 assigned to peripheral B functions, no pull-up resistor

• I/O line 24 to 27 assigned to peripheral A with Input Change Interrupt and pull-up resistor

32.6

User Interface

Each I/O line controlled by the PIO Controller is associated with a bit in each of the PIO Control-
ler User Interface registers. Each register is 32 bits wide. If a parallel I/O line is not defined,

Table 32-1.

Programming Example

Register

Value to be Written

PIO_PER

0x0000 FFFF

PIO_PDR

0x0FFF 0000

PIO_OER

0x0000 00FF

PIO_ODR

0x0FFF FF00

PIO_IFER

0x0000 0F00

PIO_IFDR

0x0FFF F0FF

PIO_SODR

0x0000 0000

PIO_CODR

0x0FFF FFFF

PIO_IER

0x0F00 0F00

PIO_IDR

0x00FF F0FF

PIO_MDER

0x0000 000F

PIO_MDDR

0x0FFF FFF0

PIO_PUDR

0x00F0 00F0

PIO_PUER

0x0F0F FF0F

PIO_ASR

0x0F0F 0000

PIO_BSR

0x00F0 0000

PIO_OWER

0x0000 000F

PIO_OWDR

0x0FFF FFF0

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