System Integration Unit

Table 4-2. GPIO Register Definitions (Sheet 2 of 2)

Register

Register Function

GPIO[15:0]

GPIO[31:16]

GPIO[47:32]

GPIO[63:48]

GPIO[79:64]

GPIO[80:84]

Type

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GRER

Detect Rising/Falling

GRER0

GRER1

GRER2

GFER

Edge

GFER0

GFER1

GFER2

 

 

 

 

 

GEDR

Detect Edge Type

GEDR0

GEDR1

GEDR2

 

 

 

 

 

 

 

 

GAFR

Set Alternate Functions

GAFR0_L

GAFR0_U

GAFR1_L

GAFR1_U

GAFR2_L

GAFR2_U

 

 

 

 

 

 

 

 

NOTE: For the alternate function registers, the designator _L signifies that the lower 16 GPIOs’ alternate functions are configured by that register and _U designates that the upper 16 GPIOs’ alternate functions are configured by that register.

Note: Write zeros to all reserved bits and ignore all reads from these bits.

Note: All GPIO registers are initialized to 0x0 at reset, which results in all GPIO pins being initialized as inputs.

4.1.3.1GPIO Pin-Level Registers (GPLR0, GPLR1, GPLR2)

Check the state of each of the GPIO pins by reading the GPIO Pin Level register (GPLR). Each bit in the GPLR corresponds to one pin in the GPIO. GPLR0[31:0] correspond to GPIO[31:0], GPLR1[31:0] correspond to GPIO[63:32] and GPLR2[16:0] correspond to GPIO[84:64]. Use the GPLR02 read-only registers to determine the current value of a particular pin (regardless of the programmed pin direction). For reserved bits, reads return zero.

Table 4-3. GPLR0 Bit Definitions

Physical Address

GPLR0

System Integration Unit

0x40E0_0000

 

 

Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Reset

PL31

PL30

PL29

PL28

PL27

PL26

PL25

PL24

PL23

PL22

PL21

PL20

PL19

PL18

PL17

PL16

PL15

PL14

PL13

PL12

PL11

PL10

PL9

PL8

PL7

PL6

PL5

PL4

PL3

PL2

PL1

PL0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bits

 

 

Name

 

 

 

 

 

 

 

 

 

 

 

Description

 

 

 

 

 

 

 

 

 

 

GPIO Pin Level ‘x’ (where x = 0 to 31).

<31:0>

PL[x]

This read-only field indicates the current value of each GPIO.

0

Pin state is low

 

 

 

 

1

Pin state is high

This is read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.

Intel® PXA255 Processor Developer’s Manual

4-7

Page 111
Image 111
Intel PXA255 manual Gpio Pin-Level Registers GPLR0, GPLR1, GPLR2, Gpio Register Definitions Sheet 2, GPLR0 Bit Definitions