Gpio alternate functions -3, Table 4-1 – Intel PXA255 User Manual
Page 107
Intel® PXA255 Processor Developer’s Manual
4-3
System Integration Unit
For more information on alternate functions, refer to the Source Unit column in
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