DS1921G_12 Datasheet, PDF (35/42 Pages) Maxim Integrated Products – Thermochron iButton

Thermochron iButton
SYMBOL
<00 to EOP>
<32 bytes>
<data>
CRC-16
FF loop
AA loop
00 loop
Command-Specific 1-Wire Communication Protocol—Legend
(continued)
DESCRIPTION
Transfer of as many 00h bytes as are needed to reach a memory page boundary
Transfer of 32 bytes
Transfer of an undetermined amount of data
Transfer of an inverted CRC-16
Indefinite loop where the master reads FFh bytes
Indefinite loop where the master reads AAh bytes
Indefinite loop where the master reads 00h bytes
Command-Specific 1-Wire Communication Protocol—Color Codes
Master-to-Slave Slave-to-Master
1-Wire Communication Examples
Write Scratchpad, Reaching the End of the Scratchpad
RST PD Select WS TA <data to EOS> CRC-16 FF loop
Write Scratchpad, Not Reaching the End of the Scratchpad
RST PD Select WS TA <data> RST PD
Read Scratchpad
RST PD Select RS TA-E/S <data to EOS> CRC-16 FF loop
Copy Scratchpad (Success)
RST PD Select CPS TA-E/S AA loop
Copy Scratchpad (Invalid TA-E/S)
RST PD Select CPS TA-E/S FF loop
Read Memory (Success)
RST PD Select RM TA <data to EOM> 00 loop
Read Memory (Invalid Address)
RST PD Select RM TA 00 loop
Reading reserved pages 20 through 63 or 68 through 127 or pages 192 and higher (beyond data-log memory)
results in 00h bytes.
______________________________________________________________________________________ 35