PAW3602DH Datasheet, PDF (15/32 Pages) Pixart Imaging Inc. – CMOS LASER MOUSE SENSOR

PixArt Imaging Inc.
PAW3602DH
CMOS Laser Mouse Sensor
7.1.2 Read Operation
A read operation, which means that data is going from the mouse sensor to the mouse controller, is always
initiated by the mouse controller and consists of two bytes. The first byte contains the address, is written by the
mouse controller, and has a “0” as its MSB to indicate data direction. The second byte contains the data and is
driven by the mouse sensor. The transfer is synchronized by SCLK. SDIO is changed on falling edges of SCLK
and read on every rising edge of SCLK. The mouse controller must go to a high Z state after the last address data
bit. The mouse sensor will go to the high Z state after the last data bit.
SCLK
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
SDIO
DO N 'T
CARE
0
A6 A5
A4 A3
H i-Z
A2 A1 A0 D7 D6
D5 D4
D3 D2
H i-Z_{_}
D1 D0
R/W bit of next
address
SDIO driven by the m ouse controller
SDIO driven by the m ouse sensor
Note "A"
Note "B"
N ote "A " ^{1. The m ouse controller sends address to the m ouse sensor.}
2. T he m ouse controller releases and set SD IO to H i-Z after the last address bit.
SCLK
7
SDIO
A1
8
A0
H i-Z
9
D7
t_HOLD
3us,m in
Note "B" 1. The m ouse sensor sends data to the m ouse controller .
2. T he m ouse sensor releases and set SD IO to H i-Z after the last data bit.
SCLK
16
SD IO
D0
H i-Z
_
1
R/W bit of next address
SDIO driven by the mouse controller
Figure 9. Read Operation
7.2 Re-Synchronous Serial Interface
If the mouse controller and the mouse sensor get out of synchronization, then the data either written or read from
the registers will be incorrect. There are two different ways for re-synchronous serial interface.
z Re-synchronous serial interface using PD pin (see Section 7.2.1)
z Re-synchronous serial interface using watchdog timer timeout (see Section 7.2.2)
Note that “watchdog timer timeout” (see Section 7.2.2) function is disabled when the mouse sensor is in the
power down mode. If the user uses this function during the power down mode, it will get out of synchronization.
The mouse sensor and the mouse controller also might get out of synchronization due to following conditions.
z Power On Problem - The problem occurs if the mouse sensor powers up before the mouse controller
sets the SCLK and SDIO lines to be output. The mouse sensor and the mouse controller might get out
of synchronization due to power on problem. An easy way to solve this is to raise PD pin (see Section
7.2.1) or use watchdog timer timeout (see Section 7.2.2) for re-synchronous serial interface.
z ESD Events - The mouse sensor and the mouse controller might get out of synchronization due to ESD
events. An easy way to solve this is to raise PD pin (see Section 7.2.1) or use watchdog timer timeout
(see Section 7.2.2) for re-synchronous serial interface.
z USB suspend - Termination of a transmission by the mouse controller may be required sometimes (for
example, due to a USB suspend interrupt during a read operation). An easy way to solve this is to raise
PD pin (see Section 7.2.1) or use watchdog timer timeout (see Section 7.2.2) for re-synchronous serial
interface.
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PixArt Imaging Inc.
E-mail: [e-mail]
V1.0, Jun. 2007