Rainbow Electronics DS2431 User Manual
Page 22
DS2431: 1024-Bit, 1-Wire EEPROM
22 of 23
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".
TA
Target Address TA1, TA2.
TA-E/S
Target Address TA1, TA2 with E/S byte.
<8 – T2:T0 bytes>
Transfer of as many bytes as needed to reach the end of the scratchpad for a given
target address.
Transfer of as many data bytes as are needed to reach the end of the memory.
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.
WRITE SCRATCHPAD (CANNOT FAIL)
RST
PD
Select
WS
TA
<8 – T2:T0 bytes>
CRC16\
FF loop
READ SCRATCHPAD (CANNOT FAIL)
RST
PD
Select
RS
TA-E/S
<8 – T2:T0 bytes>
CRC16\
FF loop
COPY SCRATCHPAD (SUCCESS)
RST
PD
Select
CPS
TA-E/S
Programming
AA loop
COPY SCRATCHPAD (INVALID ADDRESS OR PF = 1 OR COPY PROTECTED)
RST
PD
Select
CPS
TA-E/S
FF loop
READ MEMORY (SUCCESS)
RST
PD
Select
RM
TA
FF loop
READ MEMORY (INVALID ADDRESS)
RST
PD
Select
RM
TA
FF loop