AT77C104BCH08YV Atmel, AT77C104BCH08YV Datasheet - Page 21

• Manufacturer Part Number: AT77C104BCH08YV
• Manufacturer: Atmel

Specifications of AT77C104BCH08YV

• Lead Free Status / Rohs Status: Compliant

10.8
10.8.1
5347F–BIOM–3/08
YOVR
b7
0
Navigation Register
General Register
XOVR
b6
0
Register Name: Navigation (3 x 8 bits)
Access Type: Read Only (These three registers cannot be read individually. The reading com-
mand 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 code movements and clicks. The navigation registers are initialized after each read-
ing. The registers only represent actions (movement, click, transition...) that have occurred since
the last data packet sent to the host.
High (‘1’) when the Y movement counter is overflowed.
High (‘1’) when the X movement counter is overflowed.
High (‘1’) when the Y movement is negative. Low when the Y movement is positive.
High (‘1’) when the X movement is negative. Low when the X movement is positive.
This function is not in the PS/2 protocol.
Note:
• YOVR: Y Overflow
• XOVR: X Overflow
• YSIGN: Y Sign Bit
• XSIGN: X Sign Bit
• TRANS: Not used; for test purposes only.
• CLICK: Click
• FINGER: Not used; for test purposes only.
0: default
1: Y movement overflow
0: default
1: X movement overflow
0: default, positive Y movement
1: negative Y movement
0: default, positive X movement
1: negative X movement
0: default
1: click detected
In the PS/2 protocol, bits b2 and b1 are used to code the middle and right buttons respectively,
and b3 is set to high.
YSIGN
b5
0
XSIGN
b4
0
b3
1
1
TRANS
b2
0
CLICK
b1
0
AT77C104B
FINGER
b0
0
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