Rainbow Electronics DS1920 - Manual (Page 19)

DS1920
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MEMORY FUNCTION EXAMPLE Table 3
Example: Bus Master initiates temperature conversion, then reads temperature
.
MASTER MODE DATA (LSB FIRST) COMMENTS
TX Reset Reset pulse( 480-960
µ
s)
RX Presence Presence pulse
TX 55H Issue "Match ROM" command
TX <64-bit ROM code> Issue address for DS1920
TX 44H Issue "Convert Temperature" command
TX <DATA LINE HIGH> Data line is held high for at least 0.5 seconds by bus
master to allow conversion to complete.
TX Reset Reset pulse
RX Presence Presence pulse
TX 55H Issue "Match ROM" command
TX <64-bit ROM code> Issue address for DS1920
TX BEH Issue "Read Scratchpad" command.
RX <9 data bytes> 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.
TX Reset Reset pulse
RX Presence Presence pulse, done.