Datasheet

DS28EC20: 20Kb 1-Wire EEPROM
25 of 27
COMMAND-SPECIFIC 1-Wire COMMUNICATION PROTOCOL—LEGEND
SYMBOL DESCRIPTION
RST
1-Wire reset pulse generated by master.
PD
1-Wire presence pulse generated by slave.
Select
Command and data to satisfy the ROM function protocol.
WS
Command "Write Scratchpad".
RS
Command "Read Scratchpad".
CPS
Command "Copy Scratchpad".
RM
Command "Read Memory".
ERM
Command "Extended Read Memory".
TA
Target address TA1, TA2.
TA-E/S
Target address TA1, TA2 with E/S byte.
<data to EOS>
Transfer of as many bytes as needed to reach the end of the scratchpad for a given
target address.
<data to EOM>
Transfer of as many data bytes as are needed to reach the end of the memory.
<data to EOP>
Transfer of as many data bytes as are needed to reach the end of the page for a given
target address.
CRC16\
Transfer of an inverted CRC16.
FF loop
Indefinite loop where the master reads FF bytes.
AA loop
Indefinite loop where the master reads AA bytes.
Programming
Data transfer to EEPROM; no activity on the 1-Wire bus permitted during this time.
COMMAND-SPECIFIC 1-Wire COMMUNICATION PROTOCOL—COLOR CODES
Master to Slave Slave to Master Programming
WRITE SCRATCHPAD (CANNOT FAIL)
RST PD Select WS TA <Data to EOS> CRC16\ FF Loop
READ SCRATCHPAD
RST PD Select RS TA-E/S <Data to EOS> CRC16\ FF Loop
COPY SCRATCHPAD (SUCCESS)
RST PD Select CPS TA-E/S Programming AA Loop
COPY SCRATCHPAD (BS = 1 OR PF = 1 OR COPY PROTECTED)
RST PD Select CPS TA-E/S FF Loop