Intermec 073293-001 用户手册

12 

TETH_PRE
SENT 

Scanner interlock to mux internal and external 
undecoded scanners. 

0 = undecoded scanner present 
1 = no undecoded scanner present 

3.3V CMOS 

22 

TX+ 

Ethernet TX+ 

 

23 TX- 

Ethernet 

TX- 

 

24 

RX+ 

Ethernet RX+ 

 

25 RX- 

Ethernet 

RX- 

 

 

The CK30 supports USB 1.1 (12Mbps) client functionality through the 
USB_D+, USB_D- and USB_5V signals on dock interface connector J13. 
The USB client controller is built into the PXA255 processor (U2). When 
the USB connection is used for serial port emulation, the operating system 
maps it as COM1. 

USB_5V (the 5V power supplied by the USB host) is used only to detect 
the presence of a USB host; it is not used to power any CK30 hardware.  It 
is divided down to 3.3V levels by R157 and R160, and routed (as signal 
USB_WAKE) to PXA255 interrupt input GPIO19. The USB software 
driver responds to the interrupt by trying to connect to a USB host 
through the PXA255 client controller. 

If the CK30 is suspended, USB_WAKE can be configured to wake the 
system through the DOCK_WAKE path: a high-going transition on 
USB_WAKE propagates through U24, is debounced by R274, C147 and 
U33, and then is differentiated by C180 and R321. The resulting pulse 
goes through the resume logic on PXA255 GPIO1 (see “Resume Events” 
on page 65), waking the system if this wakeup is enabled (HCR U16 
output RESUME_EN is high). 

This feature is not supported in the current software. 

Note that this wakeup method can be inhibited through U24 if the dock 
port serial DCD is asserted (so CD_WAKE is high). But in most cases this 
means the CK30 is already awake. 

The CK30 supports RS-232 communications through the serial signals on 
dock interface connector J13. The signals are converted to true RS-232 
levels by U23, and brought to the “FF” UART built into the PXA255 
processor. The operating system maps this port as COM2.