DS1993 Maxim, DS1993 Datasheet - Page 9

• Manufacturer Part Number: DS1993
• Description: The DS1992/DS1993 memory iButtons (hereafter referred to as DS199_) are rugged read/write data carriers that act as a localized database, easily accessible with minimal hardware
• Manufacturer: Maxim

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
TX
RX
TX
TX
TX
TX
TX
TX
RX
TX
TX
RX
RX
RX
RX
TX
RX
TX
TX
TX
TX
TX
TX
RX
TX
TX
TX
TX
RX
TX
RX
<128 Bytes (DS1992)>
<512 Bytes (DS1993)>
DATA (LSB FIRST)
<2 data Bytes>
<2 data Bytes>
Presence
Presence
Presence
Presence
Presence
Reset
Reset
Reset
Reset
Reset
CCh
CCh
CCh
CCh
Aah
0Fh
26h
00h
26h
00h
07h
55h
26h
00h
07h
F0h
00h
00h
9 of 17
COMMENTS
Reset pulse (480µs to 960µs)
Presence pulse
Issue skip ROM command
Issue write scratchpad command
TA1, beginning offset = 6
TA2, address = 0026h
Write 2 Bytes of data to scratchpad
Reset pulse
Presence pulse
Issue skip ROM command
Issue read scratchpad command
Read TA1, beginning offset = 6
Read TA2, address = 0026h
Read E/S, ending offset = 7, flags = 0
Read scratchpad data and verify
Reset pulse
Presence pulse
Issue skip ROM command
Issue copy scratchpad command
TA1
TA2 AUTHORIZATION CODE
E/S
Reset pulse
Presence pulse
Issue skip ROM command
Issue read memory command
TA1, beginning offset = 6
TA2, address = 0000h
Read entire memory
Reset pulse
Presence pulse, done
DS1992/DS1993