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Gpio alternate functions -3, Table 4-1 – Intel PXA255 User Manual

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Intel® PXA255 Processor Developer’s Manual

4-3

System Integration Unit

For more information on alternate functions, refer to the Source Unit column in

Table 4-1

for the

appropriate section of this document.

Table 4-1. GPIO Alternate Functions (Sheet 1 of 4)

Pin

Alternate
Function Name

Alternate Function
Assignment

AF{n}
encoding

Source Unit

Signal Description and comments

GP1

GP_RST

ALT_FN_1_IN

01

Clocks & Power
Manager Unit

Active low GP_reset

GP6

MMCCLK

ALT_FN_1_OUT

01

Multimedia Card
(MMC) Controller

MMC Clock

GP7

48 MHz clock

ALT_FN_1_OUT

01

Clocks & Power
Manager Unit

48 MHz clock output

GP8

MMCCS0

ALT_FN_1_OUT

01

Multimedia Card
(MMC) Controller

MMC Chip Select 0

GP9

MMCCS1

ALT_FN_1_OUT

01

MMC Chip Select 1

GP10

RTCCLK

ALT_FN_1_OUT

01

System Integation
Unit

real time clock (1 Hz)

GP11

3.6 MHz

ALT_FN_1_OUT

01

Clocks & Power
Manager Unit

3.6 MHz oscillator out

GP12

32 kHz

ALT_FN_1_OUT

01

32 kHz out

GP13

MBGNT

ALT_FN_2_OUT

10

Memory Controller

memory controller grant

GP14

MBREQ

ALT_FN_1_IN

01

memory controller alternate bus
master request

GP15

nCS_1

ALT_FN_2_OUT

10

Active low chip select 1

GP16

PWM0

ALT_FN_2_OUT

10

PWM0 output

GP17

PWM1

ALT_FN_2_OUT

10

PWM1 output

GP18

RDY

ALT_FN_1_IN

01

Ext. Bus Ready

GP19

DREQ[1]

ALT_FN_1_IN

01

External DMA Request

GP20

DREQ[0]

ALT_FN_1_IN

01

External DMA Request

GP23

SCLK

ALT_FN_2_OUT

10

SSP Serial Port

SSP clock

GP24

SFRM

ALT_FN_2_OUT

10

SSP Frame

GP25

TXD

ALT_FN_2_OUT

10

SSP transmit

GP26

RXD

ALT_FN_1_IN

01

SSP receive

GP27

EXTCLK

ALT_FN_1_IN

01

SSP ext_clk

GP28

BITCLK

ALT_FN_1_IN

01

AC97 Controller Unit

AC97 bit_clk

BITCLK

ALT_FN_2_IN

10

I2S Controller

I2S bit_clk

BITCLK

ALT_FN_1_OUT

01

I2S bit_clk

GP29

SDATA_IN0

ALT_FN_1_IN

01

AC97 Controller Unit

AC97 Sdata_in0

SDATA_IN

ALT_FN_2_IN

10

I2S Controller

I2S Sdata_in

GP30

SDATA_OUT

ALT_FN_1_OUT

01

I2S Controller

I2S Sdata_out

SDATA_OUT

ALT_FN_2_OUT

10

AC97 Controller Unit

AC97 Sdata_out

GP31

SYNC

ALT_FN_1_OUT

01

I2S Controller

I2S sync

SYNC

ALT_FN_2_OUT

10

AC97 Controller Unit

AC97 sync

GP32

SDATA_IN1

ALT_FN_1_IN

01

AC97 Controller Unit

AC97 Sdata_in1

SYSCLK ALT_FN_1_OUT

01

I2S Controller

I2S System Clock