Rainbow Electronics DS2422 - Manual (Page 48)

DS2422
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MASTER MODE DATA (LSB FIRST) COMMENTS
TX <7 FFh bytes> Write through the end of the scratchpad
TX (Reset) Reset pulse
RX (Presence) Presence pulse
TX CCh Issue “skip ROM” command
TX AAh Issue “read scratchpad” command
RX 00h Read TA1, beginning offset=00h
RX 02h Read TA2, address=0200h
RX 1Fh Read E/S, ending offset=1Fh, flags=0h
RX <32 data bytes> Read scratchpad data and verify
TX (Reset) Reset pulse
RX (Presence) Presence pulse
TX CCh Issue “skip ROM” command
TX 99h Issue “copy scratchpad” command
TX 00h
TX 02h
TX 1Fh
TA1
TA2 (AUTHORIZATION
CODE)
E/S
TX <8 FFh bytes> Send dummy password
TX (Reset) Reset pulse
RX (Presence) Presence pulse
STEP 3
Start the new mission.
With only a single DS2422 connected to the bus master, the communication of step 3 looks like this:
MASTER MODE DATA (LSB FIRST) COMMENTS
TX (Reset) Reset pulse
RX (Presence) Presence pulse
TX CCh Issue “skip ROM” command
TX CCh Issue “start mission” command
TX <8 FFh bytes> Send dummy password
TX FFh Send dummy byte
TX (Reset) Reset pulse
RX (Presence) Presence pulse
If step 3 was successful, the MIP bit in the General Status Register will be 1, the MEMCLR bit will be 0 and the
mission start delay will count down.
PACKAGE INFORMATION
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to
www.maxim-ic.com/DallasPackInfo .)