Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Data Sheet

Product codes
AT91SAM9N12-EK
Page of 1104
221
SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]
11063K–ATARM–05-Nov-13
23.6
I/O Lines Programming Example
 is used to obtain the following configuration. 
4-bit output port on I/O lines 0 to 3, (should be written in a single write operation), open-drain, with pull-up resistor
Four output signals on I/O lines 4 to 7 (to drive LEDs for example), driven high and low, no pull-up resistor, no pull-
down 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 with pull-down resistor
I/O line 24 to 27 assigned to peripheral C with Input Change Interrupt, no pull-up resistor and no pull-down resistor
I/O line 28 to 31 assigned to peripheral D, no pull-up resistor and no pull-down resistor
Table 23-1. Programming Example
Register
Value to be Written
PIO_PER
0x0000_FFFF
PIO_PDR
0xFFFF_0000
PIO_OER
0x0000_00FF
PIO_ODR
0xFFFF_FF00
PIO_IFER
0x0000_0F00
PIO_IFDR
0xFFFF_F0FF
PIO_SODR
0x0000_0000
PIO_CODR
0x0FFF_FFFF
PIO_IER
0x0F00_0F00
PIO_IDR
0xF0FF_F0FF
PIO_MDER
0x0000_000F
PIO_MDDR
0xFFFF_FFF0
PIO_PUDR
0xFFF0_00F0
PIO_PUER
0x000F_FF0F
PIO_PPDDR
0xFF0F_FFFF
PIO_PPDER
0x00F0_0000
PIO_ABCDSR1
0xF0F0_0000
PIO_ABCDSR2
0xFF00_0000
PIO_OWER
0x0000_000F
PIO_OWDR
0x0FFF_ FFF0