Read Operation
A read operation, defined as data going from the ADNS-
5020-EN 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- con-
troller over SDIO, and has a “0” as its MSB to indicate
data direction. The second byte contains the data and
is driven by the ADNS-5020-EN over SDIO. The sensor
outputs SDIO bits on falling edges of SCLK and samples
SDIO bits on every rising edge of SCLK.
SCLK
CYCLE #
SCLK
SDIO
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
0
A6
A5
A4
A3
A2
A1
A0
D7
D6
D5
D4
D3
D2
D1
D0
SDIO DRIVEN BY MICRO-CONTROLLER
DETAIL "A"
SDIO DRIVEN BY ADNS-5020-EN
DETAIL "B"
Read Operation
t
SRAD
t
DLY
SCLK
MICROCONTROLLER
TO ADNS-5020-EN
SDIO HANDOFF
SDIO
t
SETUP
A1
A0
t
HOLD
0 ns, MIN.
Hi-Z
D7
D6
t
DLY
DETAIL "A"
0 ns, MIN.
Microcontroller to ADNS-5020-EN Handoff
DETAIL "B"
SCLK
ADNS-5020-EN TO
MICROCONTROLLER
SDIO HANDOFF
SDIO
t
DLY
t
HOLD
D
0
R/W BIT OF NEXT ADDRESS
RELEASED BY 5020
DRIVEN BY MICRO
ADNS-5020-EN to Microcontroller Handoff
NOTE:
The 0.5/f
SCLK
minimum high state of SCLK is also the
minimum SDIO data hold time of the ADNS-5020-EN. Since
the falling edge of SCLK is actually the start of the next
read or write command, the ADNS-5020-EN will hold the
state of data on SDIO until the falling edge of SCLK.
12
AVAGO [ AVAGO TECHNOLOGIES LIMITED ]
