To expand the program memory space of an 89c420, can i use a NV-SRAM type memory? Or must it be a flash type one?
This question is because on the datasheet they speack only of programming flash memory.
My target is to be able to re-program the code memory via the integrated ROM loader. So, to do that is sufficient if i connect an NV-SRAM (non flash then) chip and i connect the WR line to theone on the memory?
Or must i use a flash type one because the loader program uses flash routines to write the code data?

Thanks.