ARM ARM DUI 0224I Touchscreen controller interface, Touchscreen interface architecture, VBAT21

CLCD Display and Adaptor Board

C.3 Touchscreen controller interface

The touchscreen interface is designed to connect to a four-wire resistive touchscreen. It is driven by the TouchScreen controller TSC2200 and described in:

•Touchscreen interface architecture

•Touchscreen controller programmer’s interface on page C-13.

The Selftest program supplied on the CD demonstrates how to communicate with the touchscreen controller. The program uses the interface code to plot the touchscreen X and Y coordinates on the LCD or VGA screen.

Connectors J8 and J10 are used for the standard touchscreens provided with the CLCD assembly. Prototyping connector J3 enables the use of other resistive touchscreens, see Touchscreen prototyping connector on page C-17.

C.3.1 Touchscreen interface architecture

Figure C-7 on page C-12 shows the touchscreen interface. Table C-3 lists the touchscreen control signals. The signals to the touchscreen are routed to connector J13.

	Table C-3 Touchscreen host interface signal assignment
Signal name	Description
TSMOSI	Serial data input to controller
TS_nSS	Chip select
TSSCLK	Clock input
TSMISO	Data output
TSnDAV	Data available
TSnPENIRQ	Pen down interrupt
TSnKPADIRQ	Keypad interrupt
VBAT[2:1] and	External voltage to analog to digital converter in touchscreen
AUX[2:1]	controller. These are reserved for expansion for external devices
	connected to the AD and keypad connector J13.
R[4:1] and C[4:1]	Row and column scan signals for a keyboard. The expansion
	board switches S3 to S8 currently use eight positions on the
	scan matrix, but additional switches can be fitted using the AD
	and keypad connector J13.

ARM DUI 0224I Copyright © 2003-2010 ARM Limited. All rights reserved. C-11