Silan

Semiconductors

SC84510

HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD

Rev: 1.0

2000.12.31

6

FUNCTION DESCRIPTIONS

1. LEGACY PS/2 MOUSE OPERATING

(A) Operating mode

There are four operating modes in PS/2 mouse:

(a) Reset Mode:

In this mode a self-test is initiated during power-on or by a Reset command. After reset signal, PS/2 mouse

will send:

a Completion code AA & ID code 00.

b Set default:

* sampling rate: 100 reports/s

* non-autospeed

* stream mode

* 2 dot/count

* disable

(b) Stream Mode:

The maximum rate of transfer is the programmed sample rate.

Data report is transmitted if

aswitchis pressed

b movement has been detect

(c) Remote Mode:

Data is transmitted only in response to a Read Data command.

(d) Wrap Mode:

Any byte of data sent by the system, except hex EC (Reset wrap mode) or hex FF (Reset), is returned by

SC84510.

(B) PS/2 Mouse Data Report:

(a) In stream mode: A data report is sent at the end of a sample interval.

(b) In remote mode: A data report is sent in response to Read Data command.

(c) Data report format:

Byte

Bit

Description

1

0

Left button status; 1 = pressed

1

Right button status; 1 = pressed

2

Middle button status; 1 = pressed

3

Reserve

4

X data sign; 1 = negative

5

Y data sign; 1 = negative

6

X data overflow; 1 = overflow

7

Y data overflow; 1 = overflow

2

0~7

X data (D0~D7)

3

0~7

Y data (D0~D7)