Rainbow Electronics DS2422 - Manual (Page 12)

DS2422/DS2423
12 of 25
MEMORY FUNCTION EXAMPLE (DS2423)
Example: Write two data bytes to memory location 0026 and 0027. Read entire memory.
MASTER MODE DATA (LSB FIRST) COMMENTS
TX Reset Reset pulse (480-960 µs)
RX Presence Presence pulse
TX CCh Issue “skip ROM” command
TX 0Fh Issue “write scratchpad” command
TX 26h TA1, beginning offset=26h
TX 00h TA2, address=0026h
TX <2 data bytes> Write 2 bytes of data to scratchpad
TX Reset Reset pulse
RX Presence Presence pulse
TX CCh Issue “skip ROM” command
TX AAh Issue “read scratchpad” command
RX 26h Read TA1, beginning offset=26h
RX 00h Read TA2, address=0026h
RX 07h Read E/S, ending offset=7h, flags=0h
RX <2 data bytes> Read scratchpad data and verify
TX Reset Reset pulse
RX Presence Presence pulse
TX CCh Issue “skip ROM” command
TX 5Ah Issue “copy scratchpad” command
TX 26h
TX 00h
TX 07h
TA1
TA2
AUTHORIZATION CODE
E/S
TX Reset Reset pulse
RX Presence Presence pulse
TX CCh Issue “skip ROM” command
TX F0h Issue “read memory” command
TX 00h TA1, beginning offset=0
TX 00h TA2, address=0000h
RX <512 bytes> Read entire memory
TX Reset Reset pulse
RX Presence Presence pulse, done