AT77C105A [Preliminary]
1: watchdog enabled
Watchdog automatically stops heating of the sensor after a time-out.
•
HEATV (2 bits): Heating power value
00: 50 mW
01: 100 mW
10: reserved
11: reserved
V
DD is between 2.5 and 3.6V.
Notes: 1. Heating can only be used in the acquisition mode (it is not allowed in navigation or
click modes).
2. The oscillator has to be activated when the watchdog is required and must not be
stopped while the watchdog remains active.
Navctrl Register
Register Name: Navctrl (7 bits)
Access Type: Read/Write
Function: Navigation control
b6
b5
b4
b3
NAVV (LSB)
0
b2
b1
b0
reserved
0
NAVFREQ (LSB)
NAVV ( MSB)
0
CLICKV (MSB)
0
CLICKV (LSB)
0
NAVFREQ
(MSB)
1
0
•
NAVFREQ: Navigation frequency
00: 5.8 kHz
01: 2.9 kHz (default value)
10: 1.9 kHz
11: 1.5 kHz
A faster frequency enables faster finger movement detection. A lower frequency
enhances sensitivity. Refer to Notes 1 and 2 on page 18.
•
NAVV: Navigation pixels threshold
00: lower threshold
01:
10:
11: higher threshold
Sets the minimum analog value detected as a high level (‘1’). Refer to Note 1 on page
18.
•
CLICKV: Click pixels threshold
00: lower threshold
01:
10:
11: higher threshold
17
5419A–BIOM–01/05
ATMEL [ ATMEL ]
