PixArt Imaging Inc.
ADNS-3090 High-Performance Optical Mouse Sensor
Write Operation
Read Operation
Write operation, defined as data going from the micro- A read operation, defined as data going from the
controller to the ADNS-3090, is always initiated by the ADNS-3090 to the micro-controller, is always initiated
micro-controller and consists of two bytes. The first byte by the micro-controller and consists of two bytes. The
contains the address (seven bits) and has a “1”as its MSB
to indicate data direction. The second byte contains
the data. The ADNS-3090 reads MOSI on rising edges
of SCLK.
first byte contains the address, is sent by the micro-
controller over MOSI, and has a “0” as its MSB to indicate
data direction. The second byte contains the data and is
driven by the ADNS-3090 over MISO. The sensor outputs
MISO bits on falling edges of SCLK and samples MOSI bits
on every rising edge of SCLK.
NOTE:
The 250 ns minimum high state of SCLK is also the minimum
MISO data hold time of the ADNS-3090. Since the falling
edge of SCLK is actually the start of the next read or write
command, the ADNS-3090 will hold the state of data on
MISO until the falling edge of SCLK.
SCLK
SCLK
MOSI
tHOLD-MISO
tDLY-MISO
tHold,MOSI
D0
MISO
tSetup, MOSI
Figure 15. MOSI setup and hold time
Figure 18. MISO delay and hold time
NCS
2
1
3
4
5
6
7
8
9
12
15
16
1
2
10
11
13
14
SCLK
MOSI
A
A
A
A
A
A
A
D
D
D
D
D
D
D
D
A
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
6
1
1
MISO
MOSI Driven by Micro-Controller
Figure 16. Write Operation
NCS
SCLK
Cycle #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
SCLK
MOSI
0
A
A
A
A
A
A
A
0
6
5
4
3
2
1
MISO
D
D
D
D
D
D
D
D
0
7
6
5
4
3
2
1
tSRAD delay
Figure 17. Read operation
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PixArt Imaging Inc.
E-mail: fae_service@pixart.com.tw
16
PIXART [ PIXART IMAGING INC. ]
