Datasheet

DS1921H/Z
4 of 45
HIERARCHICAL STRUCTURE FOR 1-Wire PROTOCOL Figure 2
1-Wire net
Other
Devices
Bus
Master
Command
Level:
1-Wire ROM Function
Commands
DS1921-Specific
Memory/Control
Function Commands
DS1921
Available
Commands:
Read ROM
Match ROM
Search ROM
Skip ROM
Overdrive Skip
Overdrive Match
Conditional Search
ROM
Write Scratchpad
Read Scratchpad
Copy Scratchpad
Read Memory
Read Memory w/CRC
Clear Memory
Convert Temperature
Data Field
Affected:
64-bit Reg. #
64-bit Reg. #
64-bit Reg. #
N/A
OD-Flag
64-bit Reg. #, OD-Flag
64-bit Reg. #, Cond. Search settings,
device status
256-bit scratchpad, flags
256-bit scratchpad
4096-bit SRAM, registers, flags
All memory
All memory
Mission Time Stamp, Mission Samples
Counter, Start Delay, Sample
Rate, Alarm Time Stamps and
Durations, Histogram Memory
Memory address 211h
Cmd.
Codes:
33h
55h
F0h
CCh
3Ch
69h
ECh
0Fh
AAh
55h
F0h
A5h
3Ch
44h
64-BIT LASERED ROM Figure 3
MSB
LSB
8-Bit
CRC Code
12-Bit Temperature
Range Code
36-Bit Serial Number
8-Bit Family
Code (21h)
MSB LSB
MSB LSB
MSB LSB
MSB LSB
DEVICE
TEMP.
RANGE (°C)
RESOLUTION
(°C)
TEMP. RANGE CODE
HEX.
EQUIVALENT
DS1921H-F5 +15 to +46 0.125 0100 1111 0010 4F2
DS1921Z-F5 -5 to +26 0.125 0011 1011 0010 3B2