Intermec 073290-001 User Manual

Platform-specific peripheral control input and output signals are 
implemented through PXA255 GPIO pins, FPGA (U8) I/O pins, and 
through HCR registers U11 and U16. In general, signals are assigned 
among these devices according to these criteria: 

PXA255 
outputs: 

Used for signals that must hold their state through 
Suspend, and should not immediately be disabled on 
a critically low battery event. 

PXA255 inputs:  Used for interrupts that may need to wake the system 

from Suspend. 

HCR outputs: 

Used for peripheral enable signals that must hold their 
state through Suspend, but can and should be 
immediately “dumped” on a critically low battery 
event. 

FPGA I/O: 

Used for I/O that need not function during Suspend, 
and can default to their inactive states during 
Suspend. 

As much as possible, the signals assignments are the same as in the 700C 
class products, in order to maximize code re-use. See 609918 CX HW/SW 
Interface SRS for more detailed information. 

GP0 

PSC_IRQ* 

Interrupt from PSC PIC.  Toggles system between Run and 
Suspend. 

This is an “Always-enabled” resume source.   

PXA255 input 

↓

 = interrupt 

Can wake processor from 

Sleep 

st

ate. 

GP1 KEY_RET0 

/ 

WAKEUP* 

Computer on: 

Keypad matrix Row 0. This is also available through the FPGA.  
Duplicated here so that the eight keys in keypad Row 0 are 
functional at boot time, and can be set to wake the computer. (In 
both those instances, the FPGA is powered down.) 

Computer suspended: 

System resume interrupt from enabled keypad keys, handle trigger 
or tethered scanner trigger, dock port DCD or USB host present. 

In this usage, this pin is a wakeup interrupt only. Reading its state 
yields no information about what resume event caused the 
interrupt. 

This is an “Always-enabled” resume source.   

The resume events combined on this input are events that may be 
expected to still wake the computer after a battery change (when all 
resume pins except GPIO0 and GPIO1 will have been 
automatically disabled by the PXA255). 

PXA255 input  
↓ = interrupt