82801DB Datasheet, PDF (214/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

Functional Description
Table 5-83. Read Byte/Word Protocol without PEC
Read Byte Protocol
Bit
1
2–8
9
10
11–18
19
20
21–27
28
29
30–37
38
39
Description
Start
Slave Address - 7 bits
Write
Acknowledge from slave
Command code - 8 bits
Acknowledge from slave
Repeated Start
Slave Address - 7 bits
Read
Acknowledge from slave
Data from slave - 8 bits
NOT acknowledge
Stop
Bit
1
2–8
9
10
11–18
19
20
21–27
28
29
30–37
38
39–46
47
48
Read Word Protocol
Description
Start
Slave Address - 7 bits
Write
Acknowledge from slave
Command code - 8 bits
Acknowledge from slave
Repeated Start
Slave Address - 7 bits
Read
Acknowledge from slave
Data Byte Low from slave - 8 bits
Acknowledge
Data Byte High from slave - 8 bits
NOT acknowledge
Stop
Table 5-84. Read Byte/Word Protocol with PEC
Read Byte Protocol
Bit
1
2–8
9
10
11–18
19
20
21–27
28
29
30–37
38
39–46
47
48
Description
Start
Slave Address - 7 bits
Write
Acknowledge from slave
Command code - 8 bits
Acknowledge from slave
Repeated Start
Slave Address - 7 bits
Read
Acknowledge from slave
Data from slave - 8 bits
Acknowledge
PEC from slave
NOT Acknowledge
Stop
Bit
1
2–8
9
10
11–18
19
20
21–27
28
29
30–37
38
39–46
47
48–55
56
57
Read Word Protocol
Description
Start
Slave Address - 7 bits
Write
Acknowledge from slave
Command code - 8 bits
Acknowledge from slave
Repeated Start
Slave Address - 7 bits
Read
Acknowledge from slave
Data Byte Low from slave - 8 bits
Acknowledge
Data Byte High from slave - 8 bits
Acknowledge
PEC from slave
NOT acknowledge
Stop
214
Intel^® 82801DB ICH4 Datasheet