Rainbow Electronics DS1678 - Manual (Page 7)

DS1678
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Entering a value greater than 07FFh will result in the address location associated with the value of the
lowest 11 bits of the address.
The RTC and control registers (See Figure 2a for more detail.) are located in the main memory between
addresses 00h and 0Fh. The user NV RAM resides in locations 10h through 2Fh. The event logging
memory data port is located at locations 41h, 42h, and 43h. Memory locations 44h and up are reserved
for future extensions and will read 00h.
The end user can write only to the RTC and control registers and the user NV RAM. The rest of the
memory map is read-only from the end user’s perspective. During an event log mission, all of the
memory is read only. A write will terminate the mission. If there is an event being recorded when the
mission is terminated, the event will finish being recorded before the mission will be stopped and the
values in the MIP and ME bits will not change to 0’s until the mission has completed.
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 will be 00h.