* This specification are subject to be changed without notice.

EM85000

APPLE DESKTOP BUS MOUSE CONTROLLER

2

11.6.1995

PIN DESCRIPTIONS

Symbol

I/O

Function

DISC

I

H=discharge mode,L=non-discharge mode.(internal pull low)

LLED

O

Trackball lock led display.

V

DD

-

+5v power.

RESET

I

Low active for chip reset.

V

SS

-

GND.

X1,X2

I

Horizontal direction status for x counter data.

R

I

Right mouse key. (internal pull high)

M

I

Main mouse key. (internal pull high)

Y1,Y2

I

Vertical direction status for y counter data.

LOCK

I

Optional trackball key lock button to lock /M key. (internal pull high)

DLED

O

Active low to turn on photo LEDs.

OSCO

O

Crystal clock output.

OSCI

I

Crystal clock input.

DOUT

O

Transmit data to Host.(open drain)

DIN

I

Receive data or command from Host.

FUNCTION DESCRIPTIONS

The ADB Mouse Controller is communicated with Host by the ADB bus.Only Host sends command to mouse

controller,the mouse doesn’t send any command to the other devices or Host on the bus.The signal of the data

or command is transmitted by asynchronous protocol.First,Host sends Attention and Sync signals to synchronize

all devices on the bus,then sends command or data according the command defined.

If the addess which the device receives in command is the same as the device address,then the device will execute

this command.If there are more then two devices to contend the ADB bus,then the bus collision will happen.

Therefore,every devices must have capability to detect and to solve collision.On the contrary,if the address in

the command is not the same with the address in the device,the device will discard the command,or sends SRQ

signal to Host when device has data to be send.

COMMANDS

COMMAND

B7 B6 B5 B4 B3 B2 B1 B0

DESCRIPTION

FLUSH

A3

A2 A1 A0

0001

Mouse will clear all X,Y counter data(R0=0).

SENDRESET

-

-

-

-

0000

Soft Reset(equal power-on reset).

TALK

A3 A2 A1 A0

1

1

Rh

Rl

Controller transmits data to Host.

LISTEN

A3 A2 A1 A0

1

0

Rh

Rl

Controller receives data from Host.

OTHER

- - - - - - - - - - - - - - - - - - - - - - - - -

Reserved command.

1.B7 ~ B4:Device Address(0~F)is the position of the device.(Ref table 2)

2.B0 ~ B1:Selected Register(R0~R3),each register has two bytes.

R0:Mouse counter data register(read only by Host)

R3:Control register(can be read or written by Host)

R1,R2:No use in mouse.

3.B3,B2=11:TALK command.(1 byte)

TALK R0:IF mouse has data to report,mouse will send two bytes (R0)to Host.

IF mouse has’t data to report,Host will continue polling(R0) or execute other command.

TALK R3:Host can read mouse R3 register(2 bytes).

TALK R1,R2:No use in mouse.