"awakephd" <
a_wake@...> writes:
> With direct control of the GPIO outputs on either chip, it seems you
> could set it up to control the reset and mode pins on the
> R8C/etc. for programming without using jumpers.
That's exactly what I do :-)
> I suppose you could also use these pins to make a programmer for a
> PIC, without having to go through the gymnastics that the typical
> PIC serial programmer has to do, except for needing +12v or so
> depending on the version of the PIC. Of course, you'd still have a
> serial output available to act as a terminal, or whatever ...
I don't know PIC programming, but does it use asynchronous or
synchronous serial? Does it have any special timing requirements?
The R8C is sufficiently flexible with its timing to allow for
user-level accuracy.
The 13v requirement would take up a lot of board space if you wanted
to embed the programmer, too.
> DJ, I've done a little looking at your website. Do I understand that
> you have done a port of gcc to output code for the R8C/M16/M32
> processors? Is there a minimum program memory size needed to use
> this rather than assembler?
It depends on whether you use the default interrupt vector handling,
which requires at least 1k of flash just for that. I use gcc/C for
nearly all my R8C programming, the biggest 1B's only have about 1k of
ram and 16k of rom. checking... one of my test programs uses 2k of
flash and 318 bytes of ram, which fits in the smallest 1B's.
Of course, each C library routine you pull in (malloc, printf, etc)
adds to the needed size.