PixArt Imaging Inc.

PAW3402 / PAW3412

PS/2 Optical Mouse SOC

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PixArt Imaging Inc.

V1.0, Feb. 2008

6. Data Format

The PS/2 Mouse support two different PS/2-compatible packet formats, depending upon the following

operational modes:

•

Standard 2D mode (2D3B)

•

Standard 3D mode (3D3B)

6.1 Standard 2D Mode Format

A standard 2D PS/2-compatible mouse motion report consists of a 3-byte packet defined as below.

Byte

Bit

Symbol Description

0

BL

1 = Left button pressed

1

BR

1 = Right button pressed

2

BM

Always = 0, reserved for middle button

3

1

Always = 1, reserved for future use

4

Xs

X data sign, 1 = negative

5

Ys

Y data sign, 1 = negative

6

X data overflow, 1 = overflow

1

7

Y data overflow, 1 = overflow

2

0-7

X0~X7

X data (D0 - D7). A positive value indicates motion to the right; a

negative value indicates motion to the left. Bit 0=LSB.

3

0-7

Y0~Y7

Y data (D0 - D7), A positive value indicates device motion upward; a

negative value indicates motion downward. Bit 0=LSB.

6.2 Standard 3D Mode Format

A standard 3D PS/2-compatible mouse motion report consists of a 4-byte packet defined as below.

Byte

Bit

Symbol Description

0

BL

1= Left button pressed

1

BR

1 = Right button pressed

2

BM

1= Middle button pressed

3

1

Always = 1, reserved for future use

4

Xs

X data sign, 1 = negative

5

Ys

Y data sign, 1 = negative

6

X data overflow, 1 = overflow

1

7

Y data overflow, 1 = overflow

2

0-7

X0~X7

X data (D0 - D7). A positive value indicates motion to the right; A

negative value indicates motion to the left. Bit 0=LSB.

3

0-7

Y0~Y7

Y data (D0 - D7). A positive value indicates device motion upward; A

negative value indicates motion downward. Bit 0=LSB.

4

0-7

Z0~Z7

Z-wheel motion data (D0 - D7). A positive value indicates device

motion downward; a negative value indicates motion upward. The Z0-

Z7 limit value is ±7. Bit 0=LSB.