14

Power Up Reset

Although ADNS-3050 does have an internal power up self

reset circuitry, it is still highly recommended to follow the

power up sequence below every time power is applied.

i. Apply power

ii. Drive NCS high, then low to reset the SPI port

iii. Write 0x5a to register 0x3a

iv. Wait for at least tSWW (or tWAKEUP when performing

reset to wake up from Power Down)

v. Write 0x20 to register 0x0d

vi. Write 0x00 to register 0x41

vii.Configure the desired sensor settings accordingly

Reset

ADNS-3050 can be reset by following power up reset se-

quence. A full reset will thus be executed and any regis-

ter settings must be reloaded. The table below shows the

state of the various pins during reset.

State of Signal Pins after VDD is Valid

Pin

During Reset

After Reset

NCS

Ignored

Functional

MISO

Low

Depends on NCS

SCLK

Ignored

Depends on NCS

MOSI

Ignored

Depends on NCS

LED

High

Functional

Power Down

The ADNS-3050 can be set to power down mode by writ-

ing 0x

E7 to register 0x3B to disable the sensor.The SPI port

should not be accessed during power down. Other ICs on

the same SPI bus can be accessed, as long as the sensor‘s

NCS pin is not asserted. The table below shows the state

of various pins during power down. To exit Power Down,

reset the sensor in order to wake it up. A full reset will thus

be executed. Wait tWAKEUP before accessing the SPI port.

Any register settings must then be reloaded.

Pin

During Power Down

MOTION

Undefined

NCS

Functional*

MOSI

Functional*

SCLK

Functional*

MISO

Undefined*

*Notes:

•

NCS pin must be held to 1(HIGH) if SPI Bus is shared with other

devices, it can be in either state if the sensor is the only device to

connect to the host micro controller

•

Reading on register should only be performed after existing from the

power down mode. Any read operation during power down will not

reflect the actual data of the register.

Mode

Motion Detection Routine

Motion Polling

MOTION Interrupt

Wired

Yes

Yes

Wireless

Not Supported

Yes

Motion Polling

The micro-controller will poll the sensor for valid motion

data by checking on the MOTION_ST bit of MOTION_ST

register in a periodic cycle. If MOTION_ST bit is set, mo-

tion data in DELTA_X and DELTA_Y registers are valid and

ready to be read out by the micro-controller.

Motion polling sequence:

1. Read MOTION_ST bit of MOTION_ST register. If

MOTION_ST bit = 1, go to step 2.

2. Read DELTA_X and DELTA_Y registers consecutively

3. Optional: Read PROD_ID register to check for

communication link or sensor functionality. This

Product ID verification MUST be done only after

reading MOTION_ST, DELTA_X and DELTA_Y registers.

Motion polling is recommended to be used in the corded

application like USB gaming mouse that requires fast mo-

tion response. This feature is not supported in wireless

mode.

MOTION Interrupt

MOTION output signal (pin 3) can be used as interrupt

input to the micro-controller of the mouse triggering the

read command of motion data from the sensor whenever

there is motion detected by the sensor. The MOTION signal

is active low level-triggered output. The MOTION pin level

will be driven low as long the MOTION_ST bit in register

0x02 is set and motion data in DELTA_X and DELTA_Y reg-

isters ready to be read out by the micro-controller. Once

all the motion data has been read, DELTA_X and DELTA_Y

values become zero, MOTION bit is reset and the MOTION

pin level is driven high again.

MOTION Interrupt sequence:

1. When MOTION pin = Low, Read DELTA_X and DELTA_Y

registers consecutively.

2. Optional: Read PROD_ID register to check for

communication link or sensor functionality. This

Product ID verification MUST be done only after

reading MOTION_ST, DELTA_X and DELTA_Y registers.

MOTION interrupt should be implemented in wireless

application to lengthen battery life. It is very useful as

the main control of power management to wake up mi-

cro-controller and radio in the wireless system from rest

modes.

PixArt Imaging Inc.

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PixArt Imaging Inc.