At 14:29 30/07/2004, Jay West wrote:
Secondly, you
need to halt the device while the SRAM is loaded.
I would envision the SRAM load to
only happen once, during power up. One
could build in a reset button and dip bank switch or micro rotary switch
that would make it load different contents, but it would be up to the
operator not to do that while the system was running.
Just my idle thought, reading through this thread, but would it be possible
to provide some sort of battery backup (maybe rechargeable?) for the SRAM
on this device? Then you don't have to worry about copying out of EPROM
(or whatever) into the SRAM in those few ns as you power up the machine, as
it's already in there from last time? Have a hefty enough battery to run
the PIC/whatever, and you can even select the ROM image and re-load the
SRAM while the rest of the system is still powered off.
Rob