17

Revision_ID

Address: 0x01

Access: Read

Reset Value: 0x02

Bit

7

6

5432

1

0

Field

Data Type:

8-bit unsigned integer

USAGE:

This register contains the IC revision. It is subject to change when new IC versions are released.

Motion

Address: 0x02

Access: Read/Write

Reset Value: 0x00

Bit

76

5

4

3

2

1

0

Field

MOT

PIXRDY

PIXFIRST

OVF

Reserved

Reserved

Reserved

Reserved

Data Type:

bit field

USAGE:

Register 0x02 allows the user to determine if motion has occurred since the last time it was read. If the

MOT bit is set, then the user should read registers 0x03 and 0x04 to get the accumulated motion. Read

this register before reading the Delta_Y and Delta_X registers.

Writing anything to this register clears the MOT and OVF bits, Delta_Y and Delta_X registers. The

written data byte is not saved.

Internal buffers can accumulate more than eight bits of motion for X or Y. If either one of the internal

buffers overflows, then absolute path data is lost and the OVF bit is set. This bit is cleared once some

motion has been read from the Delta_X and Delta_Y registers, and if the buffers are not at full scale.

Since more data is present in the buffers, the cycle of reading the Motion, Delta_X and Delta_Y regis-

ters should be repeated until the motion bit (MOT) is cleared. Until MOT is cleared, either the Delta_X

or Delta_Y registers will read either positive or negative full scale. If the motion register has not been

read for long time, at 500 cpi it may take up to 16 read cycles to clear the buffers, at 1000 cpi, up to 32

cycles. To clear an overflow, write anything to this register.

The PIXRDY bit will be set whenever a valid pixel data byte is available in the Pixel_Dump register.

Check that this bit is set before reading from Pixel_Dump. To ensure that the Pixel_Grab pointer has

been reset to pixel 0,0 on the initial write to Pixel_Grab, check to see if PIXFIRST is set to high.

Field Name

Description

MOT

Motion since last report

0 = No motion

1 = Motion occurred, data ready for reading in Delta_X and Delta_Y registers

PIXRDY

Pixel Dump data byte is available in Pixel_Dump register

0 = data not available

1 = data available

PIXFIRST

This bit is set when the Pixel_Grab register is written to or when the complete

pixel array has been read, initiating an increment to pixel 0,0.

0 = Pixel_Grab data not from pixel 0,0

1 = Pixel_Grab data is from pixel 0,0

OVF

Motion overflow, _Y and/or _X buffer has overflowed since last report

0 = no overflow

1 = Overflow has occurred

PixArt Imaging Inc.

Low Power LED Integrated Slim Mouse Sensor

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PixArt Imaging Inc.