Datasheet

DS1992/DS1993
9 of 17
MEMORY FUNCTION EXAMPLES
Example: Write two data Bytes to memory locations 0026h and 0027h (the seventh and eighth Bytes of
page 1). Read entire memory.
MASTER MODE
DATA (LSB FIRST)
COMMENTS
TX
Reset
Reset pulse (480µs to 960µs)
RX
Presence
Presence pulse
TX
CCh
Issue skip ROM command
TX
0Fh
Issue write scratchpad command
TX
26h
TA1, beginning offset = 6
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 = 6
RX
00h
Read TA2, address = 0026h
RX
07h
Read E/S, ending offset = 7, flags = 0
RX
<2 data Bytes>
Read scratchpad data and verify
TX
Reset
Reset pulse
RX
Presence
Presence pulse
TX
CCh
Issue skip ROM command
TX
55h
Issue copy scratchpad command
TX
26h
TA1
TA2 AUTHORIZATION CODE
E/S
TX
00h
TX
07h
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 = 6
TX
00h
TA2, address = 0000h
RX
<128 Bytes (DS1992)>
<512 Bytes (DS1993)>
Read entire memory
TX
Reset
Reset pulse
RX
Presence
Presence pulse, done