AT77C105A [Preliminary]
Modectrl Register
Register Name: Modectrl (7 bits)
Access Type: Read/Write
Function: Mode control
b6
b5
MODE
0
b4
MODE
0
b3
b2
b1
–
b0
–
MODE (MSB)
0
MODE (LSB)
0
ANALOGRST
1
0
0
•
MODE: Select operating mode
0000: standby
0001: test (reserved for factory use)
0010: click
0100: navigation
1000: acquisition
Certain changes can be made. For example, MODE can be set to 0b0110 to activate
click and navigation.
•
ANALOGRST: Reset local oscillator
0: oscillator in active mode
1: oscillator in power-down mode
Notes: 1. Click or navigation modes cannot be used when the local oscillator is switched off..
2. To return to standby mode and stop the oscillator (to save on power consumption),
two Modectrl register accesses are necessary: the first one to select standby mode
and the second to switch off the oscillator.
3. The read-only registers cannot be read when the oscillator is turned off.
4. To shift between navigation and acquisition modes, you must be in standby mode
(Modectrl = 0b00001).
If modes such as “acquisition and click” or “acquisition and navigation” are programmed
together, they will be ignored by the system.
Programmed Mode
Register Value
01xx
11xx
1x1x
0x1x
With x = 0 or 1.
15
5419A–BIOM–01/05
ATMEL [ ATMEL ]
