Rohde & Schwarz MXO 4 Series - Page 337

Protocol analysisMXO 4 Series
337User Manual 1335.5337.02 ─ 07
Figure 13-5: I2C writes access with a 7-bit address
Address types: 7-bit and 10-bit
Target addresses can be 7 bits or 10 bits long. A 7-bit address requires 1 byte, 7 bits
for the address followed by the R/W bit.
A 10-bit address for write access requires 2 bytes: the first byte starts with the reserved
sequence 11110, followed by the two MSB of the address and the write bit. The second
byte contains the remaining 8 LSB of the address. The target acknowledges each
address byte.
S
TARGET ADDRESS
1
st
7 Bits
R/W A1
TARGET ADDRESS
2
nd
Byte
A2 DATA A
0
write
1 1 1 1 0 X X
reserved MSB
Figure 13-6: 10-bit address, write access
A 10-bit address for read access requires 3 bytes. The first 2 bytes are identical to the
write access address. The third byte repeats the address bits of the first byte and sets
the read bit.
S
TARGET ADDRESS
1
st
7 Bits
R/
W
A1
TARGET ADDRESS
2
nd
Byte
A2
DATA A
0
write
1 1 1 1 0 X X
reserved MSB
Sr
TARGET ADDRESS
1
st
7 Bits
R/
W
A3
1
read
1 1 1 1 0 X X
reserved MSB
repeated
Start
LSB
Figure 13-7: 10-bit address, read access
Trigger
The MXO 4 can trigger on various parts of I²C messages. The data and clock lines
must be connected to the input channels, triggering on math and reference waveforms
is not possible.
I²C (option R&S
MXO4-K510)