EM84520

2-IN-ONE SCROLLING MOUSE CONTROLLER

2

* This specification are subject to be changed without notice.

6.28.1999

Preliminary

Preliminary

Preliminary

Preliminary

Preliminary

FUNCTIONAL BLOCK DIAGRAM

PIN DESCRIPTIONS

OPT

I/O

INPUT: 200kohm pull low to VSS.

When OPT is connected to VDD, EM84520 will enter test mode. In test mode,

L will be the output of X1,while M will be the output of X2. Toggling R key can

change these output to be Y1,Y2 or Z1,Z2 respectively.

OUTPUT: 2kHz Z-axis LED driving source with A/D/E/F version.

"1"= VDD, "0"= floating

High duty is about 60us.

OSC.OUT

O

The RC oscillation clock output. Or 3mA sink current output for X, Y photo

emitters.

OSCR

I

Connect 50k

Ω±1% precise resistor for oscillation.

CLK/RTS

I/O

Connect to 8042 auxiliary port CLK line in PS/2 mode or connect directly to RS-

232C RTS pin in serial mode. Auto-detect the operating port by this pin.

DATA/RXD

I/O

Connect to 8042 auxiliary port DATA line in PS/2 mode or connect directly to RS-

232C RXD pin in serial mode.

R

I

Three key-switches inputs. 200k

Ω resistor pull low.

M

I/O

In Z-axis key mode, M key toggling can change the scrolling speed from low to

L

I/O

high.

X1

I

Three step dynamic input impedance. If OSC.OUT is not connected to LEDs, the

X2

I

dynamic input impedance will be off.

Y1

I

Use current comparator to measure photo-couples "ON", or "OFF".

Y2

I

Z1

I

Z-axis input.

Z2

I

Photo mode : Three steps dynamic input impedance. Current comparator input.

Key mode : 200 k

Ω resistor pull low. 7 levels increased by "M" key.

Voltage mode : 200 k

Ω resistor pull low. 7 levels voltage comparator.

Mechanical mode : 13.2k

Ω resistor pull low. Current comparator input.

VSS

Negative power.

VDD

Power line.

Symbol

I/O

Function

Z1

Z2

OPT

X1

X2

Y1

Y2

L

M

R

OSCR

OSC.OUT

C

O

M

P

A

R

A

T

O

R

M

O

T

I

O

N

D

E

T

E

C

T

O

R

D

E

B

O

U

N

C

E

COUNTER

COMMAND

STATUS

SYSTEM CLOCK

GENERATOR

RC

OSCILLATION

MULTIPLEXER

DATA

I/O

TIMING

CONTROLLER

COMPARATOR VOLTAGE

SENSOR

KEY-SWITCH

DETECTOR

Z-AXIS COUNTER

THREE TYPES SELECTOR

DATA/RXD

CLK/RTS