Re: Writing to EEPROM


"Nick" <aniket_gokhale@xxxxxxxxx> wrote in message
news:1139817947.665101.310250@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Hi,
Details what i missed:
I will be using internal EEprom - 512bytes. I will be writing to the
EEprom in Byte - Byte mode. During start up in main routine i will be
checking the POF power on flag. Jump to EEprom save routine will be
from 002bh (Brown out Interrupt).
Key questions at this point. How many bytes will you be writing?. At the
moment 'brownout' is detected, how much further can the voltage drop
before the processor stops working (normally if the brownout is at [say]
4.2v, and the processor is rated to run to 3v, you have something just
over a volt of available drop)?. How low can you get the power consumption
during this time - can you turn off all peripherals?. Given these figures,
how much capacitance must be present on the supply rail to ensure that all
the writes will complete before the power fails?. Remember that the code
in the brownout interrupt, should, once the write is complete, sit and if
the power _does not_ fail within a period of time, then check if the
voltage is good (clear the interrupt flag, and test if it comes on again),
return to the program.

Best Wishes



.

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