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Si5351A/B/C
Preliminary Rev. 0.95
15
Figure 9. I
2
C Write Operation
A read operation is performed in two stages. A data write is used to set the register address, then a data read is
performed to retrieve the data from the set address. A read burst operation is also supported. This is shown in
Figure 10.
Figure 10. I
2
C Read Operation
AC and DC electrical specifications for the SCL and SDA pins are shown in Table 7. The timing specifications and
timing diagram for the I
2
C bus is compatible with the I
2
C-Bus Standard. SDA timeout is supported for compatibility
with SMBus interfaces.
1 – Read
0 – Write
A – Acknowledge (SDA LOW)
N – Not Acknowledge (SDA HIGH)
S – START condition
P – STOP condition
From slave to master
From master to slave
Write Operation – Single Byte
S
0 A Reg Addr [7:0]
Slv Addr [6:0]
A Data [7:0]
P
A
Write Operation - Burst (Auto Address Increment)
Reg Addr +1
S
0 A Reg Addr [7:0]
Slv Addr [6:0]
A Data [7:0]
A Data [7:0]
P
A
1 – Read
0 – Write
A – Acknowledge (SDA LOW)
N – Not Acknowledge (SDA HIGH)
S – START condition
P – STOP condition
From slave to master
From master to slave
Read Operation – Single Byte
S
0 A Reg Addr [7:0]
Slv Addr [6:0]
A P
Read Operation - Burst (Auto Address Increment)
Reg Addr +1
S
1 A
Slv Addr [6:0]
Data [7:0]
P
N
S
0 A Reg Addr [7:0]
Slv Addr [6:0]
A P
S
1 A
Slv Addr [6:0]
Data [7:0]
A
P
N
Data [7:0]