7. I
2
C Interface > Block Diagram
146
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
Figure 30: I
2
C Reference Diagram
Start/Restart
Bit or Ack/Nak
Stop (P)
S/R Bit Bit Bit Bit Bit
Bit
Bit
Bit A/N
P
S/R
Byte
I2C_SDA
I2C_SCLK
S/R
P
R
PerAdr
PerAdr
WriteData
ReadData
ReadData
7 Bit Wr(0)
Slave Address
Bus
Signals
Peripheral Address
I
2
C Bus
Protocol
Data Written to Device
WriteData
S/R
P
R
7 Bit Rd(1)
Slave Address
Data Read from Device
ReadData
P
R
Restart loops to start of slave address sequence
Stop ends the transaction, bus is idle
A
Byte
A
Byte
A
Byte
K
A
A
K
A
A
A
A
A
N
I
2
C Write Data Protocol
I
2
C Read Data Protocol
= Optional
A = Ack
N = Nack
K = Ack or Nack
P = Stop
R = Restart
Note
: The I
2
C read data protocol section of this figure implies that the
peripheral addressing phase has already occurred. The I
2
C Interface will
remember where it left off such that new reads to the same device do not
require the peripheral addressing phase; however, an initial read of an I
2
C
device will require a peripheral addressing phase.