FUNCTIONAL DESCRIPTION

PIN DEFINITIONS

Copyright Semtech 2000-2001

DOC7-TS2-U860-DS-101

www.semtech.com

3

Mnemonic

Pin #

Type

Name and Function

Power:

VDD

15

P

Power Supply

VSS

14,18

P

Ground

3.3V

22

P

USB Reference Voltage Out

_Reset

13

I

Reset

Oscillators:

OSCI

16

I

Oscillator Input

OSCO

17

O

Oscillator Output

USB:

D-

35

I/O

USB D- Line

D+

36

I/O

USB D+ Line

Touch

Screen:

XR1, XR2

19,32

I/O

Touch Screen Right Drive Pins

YB1, YB2

31,20

I/O

Touch Screen Bottom Drive Pins

YT1, YT2

21,30

I/O

Touch Screen Top Drive Pins

XL1, XL2

22,29

I/O

Touch Screen Left Drive Pins

SXR

7

Al

Touch Screen Sense Pin: for X Right

SYB

6

Al

Touch Screen Sense Pin: for Y Bottom

SYT

5

Al

Touch Screen Sense Pin: for Y Top

SXL

4

Al

Touch Screen Sense Pin: for X Left

VREF

12

Al

Voltage Reference for A/D Converter

SOUT

23

O

Output control data to A/D Converter

_RB

34

I

Mouse Right Button

RDVD1-13

1-3,8-11

I/O

Reserved for future use

23-25,

27-28

33

Note: An underscore before a pin mnemonic denotes an active low signal.

Pin Types Legend: I=Input; O=Output; I/O=Input or Output; P=Power; Al= Analog Input

The UR7HCTS2-U860 consists

functionally of five major sections

(see the Functional Diagram on

Page 2). These are the Sensor

Interface, the Power Management

Section, the 16-Bit Timer, the

Oscillator Circuit and the USB

Interface.

not send resume messages to the system when it is awoken by activity on

the touch screen or button.

This IC has a built-in Oscillator

circuit capable of operations with

an external 6.00 MHz Clock source,

or a Ceramic Resonator (preferably

with built-in Load Capacitors) or a

Crystal with external Load

Capacitors.

OSCILLATOR

According to the USB specification,

if there is no activity of the USB port

for 3 ms, the system is considered

to be in a suspended state. The

detecting that the system is in

suspend, will check the state of the

touch screen and the right button.

If there is no touch pressure

detected or no button pressed, the

suspended state. In suspend the

IC fully complies with the USB

specification for the power

consumption, dissipating current

only in the USB-mandated pull-up

for the device identification.

Another technique the IC uses to

conserve power is called remote

wake-up. If the system relies on the

device to perform wake-up, the IC

will send a resume message to the

system when there is activity on the

touch screen or button.

POWER MANAGEMENT

POWER MANAGEMENT (CON’T)