Datasheet

DS2482-100: Single-Channel 1-Wire Master
10 of 22
Write Configuration
Command Code
D2h
Command Parameter
Configuration Byte
Description
Writes a new configuration byte. The new settings take effect immediately.
NOTE: When writing to the Configuration register, the new data is
accepted only if the upper nibble (bits 7 to 4) is the one's complement of
the lower nibble (bits 3 to 0). When read, the upper nibble is always 0h.
Typical Use
Defining the features for subsequent 1-Wire communication.
Restriction
1-Wire activity must have ended before the DS2482-100 can process this
command.
Error Response
Command code and parameter are not acknowledged if 1WB = 1 at the
time the command code is received and the command is ignored.
Command Duration
None; the Configuration register is updated on the rising SCL edge of the
configuration byte acknowledge bit.
1-Wire Activity
None
Read Pointer Position
Configuration register (to verify write)
Status Bits Affected
RST set to 0
Configuration Bits Affected
1WS, SPU, PPM, APU updated
1-Wire Reset
Command Code
B4h
Command Parameter
None
Description
Generates a 1-Wire Reset/Presence Detect cycle (Figure 5) at the 1-Wire
line. The state of the 1-Wire line is sampled at t
SI
and t
MSP
and the result is
reported to the host processor through the Status register, bits PPD and
SD.
Typical Use
To initiate or end any 1-Wire communication sequence.
Restriction
1-Wire activity must have ended before the DS2482-100 can process this
command.
Error Response
Command code is not acknowledged if 1WB = 1 at the time the command
code is received and the command is ignored.
Command Duration
t
RSTL
+ t
RSTH
+ maximum 262.5ns, counted from the falling SCL edge of the
command code acknowledge bit.
1-Wire Activity
Begins maximum 262.5ns after the falling SCL edge of the command
code acknowledge bit.
Read Pointer Position
Status register (for busy polling)
Status Bits Affected
1WB (set to 1 for t
RSTL
+ t
RSTH
),
PPD is updated at t
RSTL
+ t
MSP
,
SD is updated at t
RSTL
+ t
SI
Configuration Bits Affected
1WS, PPM, APU apply