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W311
Document #: 38-07703 Rev. **
Page 4 of 19
Table 3. Word Read and Word Write Protocol
Word Write Protocol
Word Read Protocol
Bit
Description
Bit
Description
1Start
1Start
2:8
Slave address – 7 bits
2:8
Slave address – 7 bits
9Write
9Write
10
Acknowledge from slave
10
Acknowledge from slave
11:18
Command Code – 8 bits
‘1xxxxxxx’ stands for byte or word operation
bit[6:0] of the command code represents the
offset of the byte to be accessed
11:18
Command Code – 8 bits
‘1xxxxxxx’ stands for byte or word operation
bit[6:0] of the command code represents the
offset of the byte to be accessed
19
Acknowledge from slave
19
Acknowledge from slave
20:27
Data byte low – 8 bits
20
Repeat start
28
Acknowledge from slave
21:27
Slave address – 7 bits
29:36
Data byte high –- 8 bits
28
Read
37
Acknowledge from slave
29
Acknowledge from slave
38
Stop
30:37
Data byte low from slave – 8 bits
38
Acknowledge
39:46
Data byte high from slave – 8 bits
47
NOT acknowledge
48
Stop
Table 4. Byte Read and Byte Write Protocol
Byte Write Protocol
Byte Read Protocol
Bit
Description
Bit
Description
1Start
1Start
2:8
Slave address – 7 bits
2:8
Slave address – 7 bits
9Write
9Write
10
Acknowledge from slave
10
Acknowledge from slave
11:18
Command Code – 8 bits
‘1xxxxxxx’ stands for byte operation
bit[6:0] of the command code represents the
offset of the byte to be accessed
11:18
Command Code – 8 bits
‘1xxxxxxx’ stands for byte operation
bit[6:0] of the command code represents the
offset of the byte to be accessed
19
Acknowledge from slave
19
Acknowledge from slave
20:27
Data byte – 8 bits
20
Repeat start
28
Acknowledge from slave
21:27
Slave address – 7 bits
29
Stop
28
Read
29
Acknowledge from slave
30:37
Data byte from slave – 8 bits
38
Not Acknowledge
39
Stop