Owner's manual
Table Of Contents
- Features
- Description
- Applications
- Specifications
- Power Consumption and DC Characteristics
- Switching Performances
- Timing Diagrams: Slow and Fast SPI Interface
- Functional Description
- Sensor and Block Diagram
- Function Registers
- SPI Interface General Description
- Control Interface (Slow SPI)
- Image Capture (Fast SPI)
- Navigation (Slow SPI)
- Temperature Stabilization Function and Watchdog
- Power Management
- Packaging Mechanical Data
- Ordering Information
- Appendix A
- Appendix B
- Appendix C
- Appendix D
18
AT77C104B
5347B–BIOM–08/04
Navigation Register
Register Name:Navigation (3 x 8 bits)
Access Type:Read Only
(these three registers cannot be read individually . The read-
ing command of the first navigation register [address 0b1000] returns the value of the
three registers).
Function:The format of the navigation registers is similar to the PS/2 protocol. Three
registers are used to codemovements and clicks. The navigation registers are initialized
after each reading. The registers only represent actions (movement, click, transition...)
that have occurred since the last data packet sent to thehost.
General Register
• YOVR: Y overflow
0: default
1: Y movement overflow
High (‘1’) when the Y movement counter is overflowed.
• XOVR: X overflow
0: default
1: X movement overflow
High (‘1’) when the X movement counter is overflowed.
• YSIGN: Y sign bit
0: default, positive Y movement
1: negative Y movement
High (‘1’) when the Y movement is negative. Low when the Y movement is positive.
• XSIGN: X sign bit
0: default, positive X movement
1: negative X movement
High (‘1’) when the X movement is negative. Low when the X movement is positive.
• TRANS: not used, for test purposes only.
• CLICK: Click
0: default
1: click detected
This function is not in the PS/2 protocol.
• FINGER: not used, for test purposes only.
b7 b6 b5 b4 b3 b2 b1 b0
YOVR XOVR YSIGN XSIGN 1 TRANS CLICK FINGER
0 0 0 0 1 0 0 0