Datasheet

Data Sheet AD9520-0
Rev. A | Page 53 of 80
Data Transfer Format
Send byte format—the send byte protocol is used to set up the register address for subsequent commands.
S Slave Address W A RAM Address High Byte A RAM Address Low Byte A P
Write byte format—the write byte protocol is used to write a register address to the RAM starting from the specified RAM address.
S Slave Address W A
RAM Address
High Byte
A
RAM Address
Low Byte
A RAM Data 0 A RAM Data 1 A RAM Data 2 A P
Receive byte format—the receive byte protocol is used to read the data byte(s) from RAM starting from the current address.
S Slave Address R A RAM Data 0 A RAM Data 1 A RAM Data 2
A
P
Read byte format—the combined format of the send byte and the receive byte.
S
Slave
Address W A
RAM Address
High Byte A
RAM Address
Low Byte A Sr
Slave
Address R A
RAM
Data 0 A
RAM
Data 1 A
RAM
Data 2
A
P
I²C Serial Port Timing
SDA
SCL
S Sr P S
t
FALL
t
SET; DAT
t
LOW
t
RISE
t
HLD; STR
t
HLD; DAT
t
HIGH
t
FALL
t
SET; STR
t
HLD; STR
t
SPIKE
t
SET; STP
t
RISE
t
IDLE
07213-165
Figure 61. I²C Serial Port Timing
Table 43. I²C Timing Definitions
Parameter Description
f
I2C
I²C clock frequency
t
IDLE
Bus idle time between stop and start conditions
t
HLD; STR
Hold time for repeated start condition
t
SET; STR
Setup time for repeated start condition
t
SET; STP
Setup time for stop condition
t
HLD; DAT
Hold time for data
t
SET; DAT
Setup time for data
t
LOW
Duration of SCL clock low
t
HIGH
Duration of SCL clock high
t
RISE
SCL/SDA rise time
t
FALL
SCL/SDA fall time
t
SPIKE
Voltage spike pulse width that must be suppressed by the input filter