VIPER
Detailed hardware description
PXA255 GPIO pin assignments
The following table summarizes the use of the 85 PXA255 GPIO pins, their direction,
alternate function and active level.
For embedded Linux the GPIO pins are setup by Redboot. Under VxWorks and
Windows CE .NET, they are setup by themselves and not by the bootloader.
Key:
AF Alternate
function.
Dir Pin
direction.
Active Function active level or edge.
Sleep Pin state during sleep mode (all Hi-Z states are to ‘1’ during sleep).
GPIO
No AF Signal Name Dir
Active Sleep Function
See
section…
0 0 ETHER_INT Input
Input Ethernet
Interrupt
1 0 PC/104_IRQ Input See
page
Input CPLD
Interrupt
2 0 USB_IRQ
Input
Input USB
Interrupt
3 0 UART_INT1 Input
Input
COM 5 Interrupt
4 0 UART_INT2 Input
Input
COM 4 Interrupt
(page
) and
(page
5 0
USER_CONFIG1
Input NA
Input User
Config 1, Jumper
LK2
User configurable jumper 1
– LK2
(page
6 0 PSU_DATA Output
NA
0
Microprocessor
Voltage DAC Data
(page
7 0
Reserved
Input NA
Input
Reserved
(page
8 0 CF_RDY
Input NA
Input CompactFLASH
Ready/nBusy
(page
and
page
9
0 BLKEN
Output High
0
LCD Backlight Enable
(page
10 0 LCDEN
Output High
0
LCD Logic Supply
Enable
(page
11 0 PSU_CLK
Output
0
Microprocessor
Core
Voltage DAC Clock
(page
12 0 SHDN
Output High
1
COM 1, 2, 3 & 4 UART
Shutdown
13 0 EN1#
Output Low
0
COM 1, 2, 3 & 4 UART
Enable
(page
© 2004 Arcom Issue H
17