ds2482-101 Maxim Integrated Products, Inc., ds2482-101 Datasheet - Page 18

• Manufacturer Part Number: ds2482-101
• Description: Single-channel 1-wire Master With Sleep Mode
• Manufacturer: Maxim Integrated Products, Inc.

Single-Channel 1-Wire Master with Sleep Mode
To write to the DS2482-101, the master must access
the device in write mode, i.e., the slave address must
be sent with the direction bit set to 0. The next byte to
be sent is a command code, which, depending on the
command, may be followed by a command parameter.
The DS2482-101 acknowledges valid command codes
and expected/valid command parameters. Additional
bytes or invalid command parameters are never
acknowledged.
To read from the DS2482-101, the master must access
the device in read mode, i.e., the slave address must
be sent with the direction bit set to 1. The read pointer
determines the register that the master reads from. The
master can continue reading the same register over
and over again, without having to readdress the device,
e.g., to watch the 1WB changing from 1 to 0. To read
from a different register, the master must issue the Set
Read Pointer command and then access the DS2482-
101 again in read mode.
18
slave address. However, some time later the slave
may refuse to accept data, possibly because of an
invalid command code or parameter. In this case,
the slave device does not acknowledge any of the
bytes that it refuses and leaves SDA high. In either
case, after a slave has failed to acknowledge, the
master first should generate a repeated START con-
dition or a STOP condition followed by a START con-
dition to begin a new data transfer.
Not Acknowledged by Master: At some time when
receiving data, the master must signal an end of
data to the slave device. To achieve this, the master
does not acknowledge the last byte that it has
received from the slave. In response, the slave
releases SDA, allowing the master to generate the
STOP condition.
______________________________________________________________________________________
Reading from the DS2482-101
Writing to the DS2482-101
See Tables 4 and 5 for the I
and data direction codes.
Table 4. I
Table 5. Data Direction Codes
SYMBOL
<byte>
WCFG
1WWB
1WRB
1WRS
1WSB
AD, 0
AD, 1
DRST
(Idle)
1WT
SRP
Sr
A\
S
P
A
I 2 C Communication Examples
2
Master-to-Slave
C Communication—Legend
START Condition
Select DS2482-101 for Write Access
Select DS2482-101 for Read Access
Repeated START Condition
STOP Condition
Acknowledged
Not Acknowledged
Bus Not Busy
Transfer of One Byte
Command “Device Reset”, F0h
Command “Set Read Pointer”, E1h
Command “Write Configuration”, D2h
Command “1-Wire Reset”, B4h
Command “1-Wire Single Bit”, 87h
Command “1-Wire Write Byte”, A5h
Command “1-Wire Read Byte”, 96h
Command “1-Wire Triplet”, 78h
DESCRIPTION
2
Slave-to-Master
C communication legend