DS2482S-800 Maxim Integrated Products, Inc., DS2482S-800 Datasheet - Page 19

• Manufacturer Part Number: DS2482S-800
• Description: Eight-channel 1-wire Master
• Manufacturer: Maxim Integrated Products, Inc.

1-Wire Reset, e.g., to begin or end 1-Wire communication
Case A: 1-Wire idle (1WB = 0), no busy polling to read the result
In the first cycle, the master sends the command; then the master waits (Idle) for the 1-Wire Reset to complete. In
the second cycle the DS2482 is accessed to read the result of the 1-Wire Reset from the Status Register.
Case B: 1-Wire idle (1WB = 0), busy polling until the 1-Wire Command is completed, then read the result
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 Write Byte, e.g., to send a command code to a 1-Wire IO channel
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 a 1-Wire IO channel
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 IO channel.
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 IO channel.
S
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
1WRS
1WRS
1WRS
1WRB
1WRB
SRP
A\
A\
A
A
A
A
A
A
A
(Idle)
Sr
E1h
33h
33h
Sr
Sr
P
P
P
P
AD,1
S
19 of 22
(Idle)
AD,1
(Idle)
AD,0
A
A
A
Repeat until the 1WB bit has changed to 0
AD,1
A
Sr
S
A
P
A
<byte>
A
<byte>
AD,1
(Idle)
AD,1
SRP
<byte>
A
A
A
A
A
<byte>
A\
<byte>
<byte>
<byte>
E1h
Repeat until the 1WB
bit has changed to 0
A\
P
A\
A\
A\
A
P
P
P
P
P