MK712

TOUCH SCREEN CONTROLLER

TOUCH SCREEN CONTROL

IDT™ TOUCH SCREEN CONTROLLER

2

MK712

REV N 051310

Pin Descriptions

Interrupts

Interrupts are controlled by register 6 (see Register Description). The INT pin (pin 2) goes high to signal an

interrupt. Interrupts are then cleared by reading any register. However, if the MK712 is in the process of generating

an interrupt during a read cycle, then the interrupt is not cleared and INT will stay high. This internal process may

take 100ns, and so to guarantee that the interrupt is cleared, two successive read cycles may be necessary.

Pin

Number

Pin

Name

Pin Type

Pin Description

1

NC

—

No connect. Do not connect this pin to anything.

2

INT

Output

Interrupt. Goes high to signal an interrupt. Cleared on next read.

3

TOUCH

Output

Touch signal. Goes low when screen is touched. Goes high when not touched.

4

VDD

Power

Power Supply. Connect to +5 V or +3.3 V. (Connect all VDDs to same voltage)

5

VDD

Power

Power Supply. Connect to +3.3 V.

6

XH

Touch Screen Pin

Connect to X-high on touch screen. (Right side)

7

XL

Touch Screen Pin

Connect to X-low on touch screen. (Left side)

8

YH

Touch Screen Pin

Connect to Y-high on touch screen. (Top)

9

YL

Touch Screen Pin

Connect to Y-low on touch screen. (Bottom)

10

GND

Power

Connect to ground.

11

GND

Power

Connect to ground.

12

WR

Input

Write enable. Active low.

13

RD

Input

Read enable. Active low.

14

CS

Input

Chip select. Active low.

15

A2

Input

Register address 2.

16

A1

Input

Register address 1.

17

A0

Input

Register address 0.

18

CLKIN

Input

Clock input. Typically 14.3 MHz. Best if driven by an IDT clock synthesizer.

19

D7

I/O

Data bit 7.

20

D6

I/O

Data bit 6.

21

GND

Power

Connect to ground.

22

VDD

Power

Power Supply. Connect to +5 V or +3.3 V. (Connect all VDDs to same voltage)

23

D5

I/O

Data bit 5.

24

D4

I/O

Data bit 4.

25

D3

I/O

Data bit 3.

26

D2

I/O

Data bit 2.

27

D1

I/O

Data bit 1.

28

D0

I/O

Data bit 0.