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Modectrl register – Rainbow Electronics AT77C105A User Manual

Page 15

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15

AT77C105A [Preliminary]

5419A–BIOM–01/05

Modectrl Register

Register Name: Modectrl (7 bits)

Access Type: Read/Write

Function: Mode control

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.

With x = 0 or 1.

b6

b5

b4

b3

b2

b1

b0

MODE (MSB)

MODE

MODE

MODE (LSB)

ANALOGRST

0

0

0

0

1

0

0

Programmed Mode

Register Value

11xx

01xx

1x1x

0x1x