Chapter 4 — Theory of Operation
FPGA IO Signal Descriptions
Function Signal Description Usage
VOL0
VOL1
VOL2
Beep volume control 000 = lowest volume
111 = highest volume
Scan_LED Scanner Good Read LED 0 = LED off
1 = LED on
Scan_LED_High Good Read LED intensity control 0 = low intensity
1 = high intensity
User_LED1 User LED1 control 0 = LED off
1 = LED on
User_LED2 User LED2 control 0 = LED off
1 = LED on
I2C Bus
The I2C bus is used for power management functions and for control of
the 2D imager, in CK30s so equipped. The PXA255 I2C controller is the
bus master; the slave devices on the bus are:
Slave Device Address See this Section
Power Supply Controller (PSC) U38 0x12 “PSC 12C Syntax” on page 59.
2D imager engine 0x40 “2D Imagers” on page 80.
The I2C bus CLK and DATA lines are pulled up through pull-up resistors
R10 and R12. Pads for an active pull-up are provided (U1), but as of the
current release this device is not installed. The PXA255 clocks the I2C bus
at approximately 93kHz.
FPGA
The CK30 architecture uses an SRAM-based FPGA for the Mini PCI and
scanner interfaces and for the keypad interface and a few GPIO functions.
For details of each functional block within the FPGA, see the document
section covering that function:
Mini PCI interface: See “Mini PCI Interface” on page 69.
Scanner interfaces: See “Scanners” on page 74.
Keypad interface: See “Key Matrix Scanning” on page 67.
Volume control: See “Beeper” on page 92.
CK30 Handheld Computer Service Manual 47
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