Write Operation
Read Operation
Write operation, defined as
data going from the micro-
controller to the ADNS-3040,
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
A read operation, defined as
data going from the ADNS-
3040 to the micro-controller, is
always initiated by the micro-
controller and consists of two
bytes. The first byte contains
the address, is sent by the
micro-controller over MOSI,
SCLK
tHOLD MISO
tDLY - MISO
MISO
D0
Figure 16. MISO Delay and Hold Time
to indicate data direction. The and has a “0” as its MSB to
NOTE:
The 0.5/f
second byte contains the data.
The ADNS-3040 reads MOSI
on rising edges of SCLK.
indicate data direction. The
second byte contains the data
and is driven by the ADNS-
3040 over MISO. The sensor
outputs MISO bits on falling
edges of SCLK and samples
MOSI bits on every rising edge
of SCLK.
minimum high state of SCLK is
SCLK
also the minimum MISO data hold time of the
ADNS-3040. Since the falling edge of SCLK is
actually the start of the next read or write
command, the ADNS-3040 will hold the state of
data on MISO until the falling edge of SCLK.
NCS
2
1
3
4
5
6
7
8
9
12
15
16
1
2
10
11
13
14
SCLK
MOSI
A6
A5
A4
A3
A2
A1
A0
D7
D6
D5
D4
D3
D2
D1
D0
A6
1
1
MISO
MOSI Driven by Micro Controller
Figure 13. Write Operation
SCLK
MOSI
tHold,MOSI
tsetup,MOSI
Figure 14. MOSI Setup and Hold Time
NCS
SCLK
Cycle #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
SCLK
MOSI
0
A6
A5
A4
A3
A2
A1
A0
D0
MISO
D7
D6
D5
D4
D3
D2
D1
Figure 15. Read Operation
tSRAD delay
12
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