ADNS-3000 Avago Technologies US Inc., ADNS-3000 Datasheet - Page 13

• Manufacturer Part Number: ADNS-3000
• Description: Low Power Wireless LED Sensor
• Manufacturer: Avago Technologies US Inc.

Specifications of ADNS-3000

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 516-2308-5

Synchronous Serial Port
The synchronous serial port is used to set and read pa-
rameters in the ADNS-3000, and to read out the motion
information. The port is a four wire serial port. The host
micro-con troller always initiates communication; the
ADNS-3000 never initiates data transfers. SCLK, MOSI, and
NCS may be driven directly by a micro-controller. The port
pins may be shared with other SPI slave devices. When the
NCS pin is high, the inputs are ignored and the output is
at tri-state.
The lines that comprise the SPI port:
SCLK: Clock input. It is always generated by the master
MOSI: Input data. (Master Out/Slave In)
MISO: Output data. (Master In/Slave Out)
NCS: Chip select input (active low). NCS needs to be low to
Chip Select Operation
The serial port is activated after NCS goes low. If NCS is
raised during a transaction, the entire transaction is
aborted and the serial port will be reset. This is true for
all transactions. After a transaction is aborted, the normal
address-to-data or transaction-to-transaction delay is
still required before beginning the next transaction. To
improve communication reliability, all serial transac tions
should be framed by NCS. In other words, the port should
not remain enabled during periods of non-use because
ESD and EFT/B events could be interpreted as serial com-
munication and put the chip into an unknown state. In ad-
dition, NCS must be raised after each burst-mode transac-
tion is complete to terminate burst-mode. The port is not
available for further use until burst-mode is terminated.
Power Management Modes
The ADNS-3000 has three power-saving modes. Each
mode has a different motion detection period with its
respective response time to mouse motion. Response
Time is the time taken for the sensor to ‘wake up’ from rest
mode when motion is detected. When left idle, the sen-
sor automatically changes or downshift from Run mode
to Rest1, to Rest2 and finally to Rest3 which consumes the
least current. Do note that current consumption is the low-
est at Rest3 and highest at Rest1, however time required
for sensor to respond to motion from Rest1 is the short-
est and longest from Rest3. Downshift Time is the elapsed
time (under no motion condition) from current mode to
the next mode for example, it takes 10s for the sensor that
is in Rest1 to change to Rest2. The typical response time
and downshift time for each mode is shown in the fol-
lowing table. However, user can change the default time
setting for each mode via register 0x0e through 0x13.
13
(the micro-controller).
activate the serial port; otherwise, MISO will be high
Z, and MOSI & SCLK will be ignored. NCS can also be
used to reset the serial port in case of an error.
Note:
These default timings are subject to changes after characterization.
Another feature in ADNS-3000 that can be used to opti-
mize the power consumption of the optical mouse system
is the Motion Interrupt Output or MOTION pin (pin 3). It
allows the host controller to be in sleep mode (or low-
est operating current mode) when there is no motion
detected after some time instead of consistently be in
active mode and polling motion data from the sensor. When
motion is detected, the sensor will send the motion inter-
rupt signal through pin 3 to the controller to wake it up
from sleep mode to resume its motion detection routine
for navigation position and direction update.
MOTION Detection Routine
Typically in the motion detection routine, MCU will poll
the sensor for valid motion data by checking on the
MOTION_ST bit in MOTION_ST register. If MOTION_ST bit
is set, motion data in DELTA registers is valid and ready to
be read by the MCU. For 8-bit motion reporting the DELTA
registers are DELTA_X and DELTA_Y and for 12-bit motion
reporting the DELTA registers are DELTA_X, DELTA_Y and
DELTA_XY_HIGH.
MOTION Function
MOTION output signal (pin 3) can be used as interrupt in-
put to the microcontroller of the mouse to trigger the con-
troller to read the motion data from the sensor whenever
there is motion detected by the sensor. The MOTION signal
can be configured to be level or edge triggered, active
high or low by setting the bits in MOTION_CTRL register.
For active high level-triggered configuration, the MOTION
pin level will be driven high as long the MOTION bit in
register 0x02 is set and there is motion data in DELTA
registers ready to be read by the microcontroller. Once
all the motion data has been read, DELTA registers value
become zero, MOTION bit is reset and the MOTION pin
level is driven low.
For active high edge-triggered configuration, a pulse of
380ns (typical) will be sent through the MOTION pin when
there is motion detected by the sensor during rest modes.
The pulse can be used as interrupt input to activate the
microcontroller from its sleep mode to enter into run
mode to start polling the sensor for motion data by moni-
toring MOTION_ST bit (set whenever there is valid motion
data) in MOTION register (0x02) and reading DELTA regis-
ters until MOTION_ST bit is reset.
Mode
Rest 1
Rest 2
Rest 3
Response Time
(Typical)
20 ms
100 ms
500 ms
Downshift Time
(Typical)
<1 s
10 s
600 s