PixArt Imaging Inc.
ADBS-A350 Optical Finger Navigation
If the rising edge of SCLK for the last address bit of the read command occurs before the required delay (t
command may not complete correctly.
), the write
SWR
tSRW & tSRR
tSRAD
SCLK
Address
Data
Address
Read Operation
Figure 17. Timing between read and either write or subsequent read commands
Next Read or
Write Operation
During a read operation SCLK should be delayed at least Burst mode is activated by writing 0x10 to register 0x1c
after the last address data bit to ensure that the IO_MODE. Then the burst mode data can be read by
t
SRAD
ADBS-A350 has time to prepare the requested data. The
falling edge of SCLK for the first address bit of either the respond with the contents of the Motion, Delta_Y, Delta_X,
read or write command must be at least t or t after SQUAL, Shutter_Upper, Shutter_Lower and Maximum_
reading the Motion register 0x02. The ADBS-A350 will
SRR
SRW
the last SCLK rising edge of the last data bit of the previous
read operation.
Pixel registers in that order. The burst transaction can be
terminated after the first 3 bytes of the sequence are read
by bringing the NCS pin high. After sending the register
Burst Mode Operation
address, the micro-controller must wait t
and then
SRAD
begin reading data. All data bits can be read with no delay
between bytes by driving SCLK at the normal rate.The data
is latched into the output buffer after the last address bit
is received. After the burst transmission is complete, the
Burst mode is a special serial port operation mode that
may be used to reduce the serial transaction time for a
motion read. The speed improvement is achieved by con-
tinuous data clocking from multiple registers without the
need to specify the register address, and by not requiring
the normal delay period between data bytes.
micro-controller must raise the NCS line for at least t
BEXIT
to terminate burst mode. The serial port is not available
for use until it is reset with NCS, even for a second burst
transmission.
tSRAD
SCLK
Motion Register Address
Read First Byte
First Read Operation
Figure 18. Motion Burst Timing
Read Second Byte
Read Third Byte
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PixArt Imaging Inc.
E-mail: fae_service@pixart.com.tw
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