DS1920-F3 Maxim Integrated Products, DS1920-F3 Datasheet - Page 19

• Manufacturer Part Number: DS1920-F3
• Description: Temperature Ibutton
• Manufacturer: Maxim Integrated Products

MEMORY FUNCTION EXAMPLE Table 3
Example: Bus Master initiates temperature conversion, then reads temperature
MASTER MODE
TX
RX
TX
TX
TX
TX
TX
RX
TX
TX
TX
RX
TX
RX
<DATA LINE HIGH>
DATA (LSB FIRST)
<64-bit ROM code>
<64-bit ROM code>
<9 data bytes>
Presence
Presence
Presence
Reset
Reset
Reset
BEH
55H
44H
55H
19 of 22
Reset pulse( 480-960 s)
Presence pulse
Issue "Match ROM" command
Issue address for DS1920
Issue "Convert Temperature" command
Data line is held high for at least 0.5 seconds by bus
master to allow conversion to complete.
Reset pulse
Presence pulse
Issue "Match ROM" command
Issue address for DS1920
Issue "Read Scratchpad" command.
Read entire scratchpad plus CRC; the master now
recalculates the CRC of the eight data bytes received
from the scratchpad, compares the CRC calculated and
the CRC read. If they match, the master continues; if
not, this read operation is repeated.
Reset pulse
Presence pulse, done.
COMMENTS
.
DS1920