Datasheet

Si5351A/B/C-B
Rev. 1.0 17
Data is transferred MSB first in 8-bit words as specified by the I
2
C specification. A write command consists of a 7-
bit device (slave) address + a write bit, an 8-bit register address, and 8 bits of data as shown in Figure 9. A write
burst operation is also shown where every additional data word is written using to an auto-incremented address.
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 8. 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] PA
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] PA
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 ASlv Addr [6:0] Data [7:0] PN
S 0 A Reg Addr [7:0]Slv Addr [6:0] A P
S 1 ASlv Addr [6:0] Data [7:0] A PNData [7:0]