PAW3212DB-TJDT Datasheet, PDF (17/31 Pages) Pixart Imaging Inc. – ULTRA LOW POWER WIRELESS MOUSE SENSOR

PAW3212DB-TJDT
10. Pin1 Functions in 2-wired SPI Mode
After the sensor has been successfully switched to 2-wired SPI mode, the NCS pin will lose its original function in 3-wired SPI mode. Thus
the NCS pin (Pin1) can be further switched to the following three different functions according to Pin1_Sel bits (bit 5 and 4) in register
SPI_Sel (address 0x26).
Hardware Reset Function
The host controller can assert Pin1 to reset the sensor. A full chip reset will thus be executed, just like the effect of using Software Reset
Function. After the reset, all the recommended register settings must be reloaded to ensure the sensor works properly.
Quick Burst (QB) Function
This function is to reduce the host controller SPI access time thus to save the power of the host controller. In QB mode, the host controller
doesn’t need to specify the sensor address through SPI interface to get sensor motion data.
Traditional way of reading sensor motion data
MOTION
(from sensor)
2-wired SPI
0x02
Motion
Status
Read Motion_Status
0x03 X[7:0]
Read X[7:0]
0x04 Y[7:0]
Read Y[7:0]
0x12 XY_Hi
Read X[11:8], Y[11:8]
Quick Burst function to read sensor motion data
MOTION
(from sensor)
QB (Pin1)
(from host)
tQB = 2us(min)
2-wired SPI
X[7:0]
Y[7:0]
XY_Hi
X[7:0]
Y[7:0]
XY_Hi
Figure 19. Reading motion data via Quick Burst function and traditional function
Hardware Power-Down Function
The host controller can assert Pin1 to force the sensor operated at extremely low power state, just like the effect of using Software Power-
Down function.
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