Atmel SAM4L Xplained Pro Evaluation Kit Atmel ATSAM4L-XPRO ATSAM4L-XPRO Data Sheet

42023E–SAM–07/2013

ten to one. Again all bits written to zero remain unchanged. Note that for some registers (e.g.
IFR), not all access methods are permitted.

Note that for ports with less than 32 bits, the corresponding control registers will have unused
bits. This is also the case for features that are not implemented for a specific pin. Writing to an
unused bit will have no effect. Reading unused bits will always return 0. 

GPIO Register Memory Map

0x000

GPIO Enable Register

Read/Write

GPER

Read/Write

Y

N

0x004

GPIO Enable Register

Set

GPERS

Write-only

Y

N

0x008

GPIO Enable Register

Clear

GPERC

Write-only

Y

N

0x00C

GPIO Enable Register 

Toggle

GPERT

Write-only

Y

N

0x010

Peripheral Mux Register 0

Read/Write

PMR0

Read/Write

Y

N

0x014

Peripheral Mux Register 0

Set

PMR0S

Write-only

Y

N

0x018

Peripheral Mux Register 0

Clear

PMR0C

Write-only

Y

N

0x01C

Peripheral Mux Register 0

Toggle

PMR0T

Write-only

Y

N

0x020

Peripheral Mux Register 1

Read/Write

PMR1

Read/Write

Y

N

0x024

Peripheral Mux Register 1

Set

PMR1S

Write-only

Y

N

0x028

Peripheral Mux Register 1

Clear

PMR1C

Write-only

Y

N

0x02C

Peripheral Mux Register 1

Toggle

PMR1T

Write-only

Y

N

0x030

Peripheral Mux Register 2

Read/Write

PMR2

Read/Write

Y

N

0x034

Peripheral Mux Register 2

Set

PMR2S

Write-only

Y

N

0x038

Peripheral Mux Register 2

Clear

PMR2C

Write-only

Y

N

0x03C

Peripheral Mux Register 2

Toggle

PMR2T

Write-only

Y

N

0x040

Output Driver Enable Register

Read/Write

ODER

Read/Write

Y

N

0x044

Output Driver Enable Register

Set

ODERS

Write-only

Y

N

0x048

Output Driver Enable Register

Clear

ODERC

Write-only

Y

N

0x04C

Output Driver Enable Register

Toggle

ODERT

Write-only

Y

N

0x050

Output Value Register

Read/Write

OVR

Read/Write

N

N

0x054

Output Value Register

Set

OVRS

Write-only

N

N

0x058

Output Value Register

Clear

OVRC

Write-only

N

N

0x05c

Output Value Register

Toggle

OVRT

Write-only

N

N

0x060

Pin Value Register

Read

PVR

Read-only

Depe
nding 

on pin 
states

N

N