Reply to:   RE>Questions about power, clock

Q1 Yes, Program memory can programmed/erased with the pickstart board for
erasable parts.

Q3. Yes, the fuses can be re-programmed with the programmer. Obviously if the
code protect fuse was blown then un-blowing it doesn't make the code
unproteced.

Q4. Don't know, but if time keeping is critical why not use a 32kHz watch
crystal as the low frequency might still keep power consumption low enough.
-Karl

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Date: 3/21/95 6:03
To: Karl Grabe
From: pic microcontroller discussion
Further some readings about several microcontroller lines, I've decided to use
the PIC serie of my applications. I just got my PICSTART16B development board
and hope to have my first hands-on experiences very soon (so you may say I'm a
novice). There're still few points I'd like to clarify; any help would greatly
be appreciated.

1)  The 16C84 is an EEPROM device.  Am I correct to assume that the program
memory can be erased?  If so, how?  With the PICSTART board?

2)  Power consumption is minimal (~15uA) in the LP mode.  Will it be about the
same in RC mode running at about 32kHz?

3)  The options (clock mode, etc.) are selected with what is refered to as
<fuses>.  On the erasable parts, are they burned permanently or are they
erased along with the program memory?

4)  With the clock running in RC mode, substantial variations in frequency is
expected due to parts-to-parts variations (R, C, PIC itself, Vcc, etc.). For
given parts and conditions, what about the short term stability?  For
instance,
if the 60Hz is used as the primary clock, with the PIC keeping track of the
interval between cycles; is the RC clock stable enough to be used for backup
clock for let say few hours?

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Marc Dion                                Defence Research Establishment Ottawa