DS1683_12 Datasheet, PDF (9/21 Pages) Maxim Integrated Products – Total-Elapsed-Time and Event Recorder with Alarm

DS1683
Total-Elapsed-Time and Event Recorder with Alarm
COMMUNICATIONS KEY
S START A ACK
WHITE BOXES INDICATE THE MASTER IS
CONTROLLING SDA
P STOP
N
NOT
ACK
SHADED BOXES INDICATE THE SLAVE IS
CONTROLLING SDA
Sr
REPEATED
START
X X X X X X X X 8-BIT ADDRESS OR DATA
NOTES
1) ALL BYTES ARE SENT MOST SIGNIFICANT BIT FIRST.
2) THE FIRST BYTE SENT AFTER A START CONDITION
IS ALWAYS THE SLAVE ADDRESS FOLLOWED BY THE
READ/WRITE BIT.
WRITE THE 4-BYTE PASSWORD VALUE (REGISTERS 1Ah THROUGH 1Dh) WITH A SINGLE TRANSACTION TO SLAVE ADDRESS D6h
S 11010110 A 00011010 A
BYTE 1
A
BYTE 2
A
BYTE 3
A
BYTE 4
AP
WRITE THE 4-BYTE PASSWORD ENTRY (REGISTERS 02h THROUGH 05h) WITH A SINGLE TRANSACTION TO SLAVE ADDRESS D6h
S 11010110 A 00000010 A
BYTE 1
A
BYTE 2
A
BYTE 3
A
BYTE 4
AP
Figure 3. Password Value and Password Entry I²C Examples
If the Password Value has been changed from the factory
default setting, the user has to enter this new password
value into the PWE registers after a power cycle in order
to unlock the memory again.
See Figure 3 for examples of writing the 4-byte Password
Value and the 4-byte Password Entry value.
User Memory
The DS1683 has 16 bytes of user-programmable,
EEPROM memory. User memory is set to read-only if
the correct password is not entered into the Password
Entry Bytes. If the correct password is entered into the
Password Entry Bytes, the data can be written to the User
Memory and stored in EEPROM with the correct I²C write
command.
Maxim Integrated
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