PixArt Imaging Inc.

PAW3501UI

USB Optical Mouse Sensor Single Chip

All rights strictly reserved any portion in this paper shall not be reproduced, copied or transformed to any other forms without permission.

7

PixArt Imaging Inc.

V2.1 April. 2008

5. USB Interface

5.1 USB Command Set Description (USB Descriptor)

The USB HOST detects USB mouse device plug-in and assigns a new unique address to the USB mouse device,

then asking USB mouse device for information about the device description, configuration description, and

assigning a configuration value for USB mouse device during enumeration period. After enumeration, the USB

mouse device is able to transfer motion and button value to the USB host.

Descriptor Type

Byte

Byte

Byte

Byte

Byte

Byte

Byte

Byte

12

01

10

01

00

00

00

08

3A

09

00

25

00

01

01

02

Device Descriptor (18 bytes)

00

01

09

02

22

00

01

01

04

A0

Configuration Descriptor (9 bytes)

32

09

04

00

00

01

03

01

02

Interface Descriptor (9 bytes)

00

09

21

10

01

00

01

22

48

Human Interface Device Descriptor

(9 bytes)

00

Endpoint Descriptor (7 bytes)

07

05

81

03

04

00

0A

05

01

09

02

A1

01

05

09

19

01

29

03

15

00

25

01

95

03

75

01

81

02

95

01

75

05

81

03

05

01

09

01

A1

00

09

30

09

31

15

81

25

7F

75

08

95

02

81

06

C0

09

38

95

01

81

06

09

3C

15

00

25

01

75

01

95

Human Interface Device Report

Descriptor (72 bytes, 3D3B)

01

B1

22

95

07

B1

01

C0

5.2 USB Data Report Format

The USB report has two data formats, depending on boot or report protocol is selected. One kind of data format

is the boot protocol used in legacy environment as 4.2.1. The other kind of data format is USB report protocol

format which includes Z-wheel movement data in the fourth byte as 4.2.2. The Z-wheel is moved forward the

fourth byte data is 01H, the Z-wheel is moved backward the fourth byte data is FFH, and the Z-wheel is idle the

fourth byte data is 00H.

5.2.1 USB Boot Protocol for Legacy Operation

Byte

Bit

Symbol

Description

0

BL

1 = Left button pressed

1

BR

1 = Right button pressed

1

2 ~ 7

NC

Reserved

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.