PAN301A Datasheet, PDF (14/24 Pages) List of Unclassifed Manufacturers – CMOS HIGH PERFORMANCE OPTICAL MOUSE SENSOR

PixArt Imaging Inc.
PAN301A
CMOS Optical Mouse Sensor
6. Serial Interface
The synchronous serial port is used to set and read parameters in the PAN301A, and can be used to read
out the motion information instead of the quadrature data pins.
SCLK: The serial clock line. It is always generated by the host micro-controller.
SDIO: The serial data line used for write and read data.
PD: A third line is sometimes involved. PD(Power Down pin) is usually used to place the PAN301A
in a low power mode to meet USB suspend specification. PD can also be used to force re-
synchronization between the micro-controller and the PAN301A in case of an error.
6.1 Transmission Protocol
The transmission protocol is a two-wire link, half duplex protocol between the micro-controller and
PAN301A. All data changes on SDIO are initiated by the falling edge on SCLK. The host micro-
controller always initiates communication; the PAN301A never initiates data transfers.
The transmission protocol consists of the two operation modes:
- Write Operation.
- Read Operation.
Both of the two operation modes consist of two bytes. The first byte contains the address (seven bits) and
has a bit7 as its MSB to indicate data direction. The second byte contains the data.
FIRST BYTE
SECOND BYTE
R /W
(1 BIT)
ADDRESS (7 BIT)
DATA (8 BIT)
MSB
LSB MSB
LSB
Figure 9. Transmission protocol
6.1.1 Write Operation
A write operation, which means that data is going from the micro-controller to the PAN301A, is always
initiated by the micro-controller and consists of two bytes. The first byte contains the address (seven bits)
and has a “1” as its MSB to indicate data direction. The second byte contains the data. The transfer is
synchronized by SCLK. The micro-controller changes SDIO on falling edges of SCLK. The PAN301A
reads SDIO on rising edges of SCLK.
SCLK
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
SDIO
DON'T
CARE
1
A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
DON'T
CARE
SDIO driven by Micro-controller
Figure 10. Write operation
6.1.2 Read Operation
A read operation, which means that data is going from the PAN301A to the micro-controller, is always
initiated by the micro-controller and consists of two bytes. The first byte contains the address, is written
by the micro-controller, and has a “0” as its MSB to indicate data direction. The second byte contains the
data and is driven by the PAN301A. The transfer is synchronized by SCLK. SDIO is changed on falling
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PixArt Imaging Inc.
E-mail: [e-mail]
V1.3, MAY. 2004