DS1678 Maxim, DS1678 Datasheet - Page 10

• Manufacturer Part Number: DS1678
• Description: The DS1678 real-time clock (RTC) event recorder records the time and date of a nonperiodic, asynchronous event each time the active-low INT pin is activated
• Manufacturer: Maxim

The user can write only to the RTC, control registers, and user NV RAM. The rest of the memory map is
read-only from the user’s perspective. During an event-log mission, all the memory is read-only. A write
terminates the mission. If there is an event being recorded when the mission is terminated, the event
finishes being recorded before the mission is stopped, and the values in the MIP and ME bits do not
change to zeros until the mission is complete.
During an event-log mission, memory locations 30h and above are not accessible to the user to avoid data
collisions from a user read and an event being logged at the same time. If the user tries to read a location
with an address greater than 2Fh during a mission, the value returned is 00h.
Table 3. DS1678 Event Elapsed Time Duration
ADDRESS REGISTE
07FD
07FB
07FC
07FE
07FF
0000
0001
0002
0003
0004

Event 1 Elapsed Time from Last Event Counter LSB
Event 1 Elapsed Time from Last Event Counter MSB
Event 2 Elapsed Time from Last Event Counter LSB
Event 2 Elapsed Time from Last Event Counter MSB
Event 1023 Elapsed Time from Last Event Counter LSB
Event 1023 Elapsed Time from Last Event Counter MSB
Event 1024 Elapsed Time from Last Event Counter LSB
Event 1024 Elapsed Time from Last Event Counter MSB

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