DS2482-100 Dallas Semiconducotr, DS2482-100 Datasheet - Page 18

• Manufacturer Part Number: DS2482-100
• Description: Single-Channel 1-Wire Master
• Manufacturer: Dallas Semiconducotr

1-Wire Write Byte, e.g., to Send a Command Code to the 1-Wire Line
Case A: 1-Wire idle (1WB = 0), No Busy Polling
33h is the valid 1-Wire ROM function command for Read ROM. The idle time is needed for the 1-Wire function to
complete. There is no data read back from the 1-Wire line with this command.
Case B: 1-Wire Idle (1WB = 0), Busy Polling Until the 1-Wire Command is Completed.
When 1WB has changed from 1 to 0, the 1-Wire Write Byte command is completed.
Case C: 1-Wire Busy (1WB = 1)
The master should stop and restart as soon as the DS2482 does not acknowledge the command code.
1-Wire Read Byte, e.g., to Read a Byte from the 1-Wire Line
Case A: 1-Wire Idle (1WB = 0), No Busy Polling, Set Read Pointer After Idle Time
The idle time is needed for the 1-Wire function to complete. Then set the read pointer to the Read Data register
(code E1h) and access the device again to read the data byte that was obtained from the 1-Wire line.
Case B: 1-Wire Idle (1WB = 0), No Busy Polling, Set Read Pointer Before Idle Time
The read pointer is set to the Read Data register (code E1h) while the 1-Wire Read Byte command is still in
progress. Then, after the 1-Wire function is completed, the device is accessed to read the data byte that was
obtained from the 1-Wire line.
Case C: 1-Wire Idle (1WB = 0), Busy Polling Until the 1-Wire Command is Completed
Poll the Status register until the 1WB bit has changed from 1 to 0. Then set the read pointer to the Read Data
register (code E1h) and access the device again to read the data byte that was obtained from the 1-Wire line.
Case D: 1-Wire Busy (1WB = 1)
The master should stop and restart as soon as the DS2482 does not acknowledge the command code.
Sr
S
S
S
S
S
S
S
S
AD,0
AD,0
AD,0
AD,0
AD,0
AD,0
AD,0
AD,0
AD,0
A
A
A
A
A
A
A
A
A
1WWB
1WWB
1WWB
1WRB
1WRB
1WRB
1WRB
SRP
SRP
A\
A\
A
A
A
A
A
A
A
(Idle)
Sr
Sr
E1h
E1h
33h
33h
Sr
P
P
P
AD,1
AD,1
S
18 of 21
(Idle)
AD,0
A
A
A
A
AD,1
A
A
Sr
Sr
P
A
<byte>
<byte>
A
(Idle)
AD,1
AD,1
SRP
<byte>
A
A
A
A
A
<byte>
<byte>
A\
<byte>
<byte>
Repeat until the 1WB
bit has changed to 0.
E1h
Repeat until the 1WB
bit has changed to 0.
A\
A\
P
A\
A\
A
P
P
P
P