Very cool, and very helpful. As I was digging around for suppliers for the FT232R chip, I also came across the Silicon Lab CP2103 chip. One source described this chip as "superior to the FTDI chip" -- but I can't see that there is any significant difference?? Except that the CP2103 is only available in a 28-QFN package, which I'm guessing will be a lot harder for a home-brew novice like myself to solder to the board.
Am I missing something in the comparison between the FT232R and the CP2103??
Andy
--- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@...> wrote:
>
>
> "awakephd" <a_wake@...> writes:
> > I'd like to hear more about this one -- are you saying that you
> > don't need anything other than a serial output -- no JDM-type board
> > or anything? I assume there is a pin that must be signalled to put
> > it in programming mode? Does it use a fixed baud rate, or ??
> >
> > This part sure does sound interesting!!
>
> Go to http://people.redhat.com/~dj/m32c/
>
> Click on "Easy R8C/M16C/M32C Flash Programming" and read :-)
>
> The link under it is a sample flash downloader program.
>
> Basically, you need three things to program:
>
> 1. To be able to reset the chip (duh)
>
> 2. To be able to assert the MODE or CnVss pin (a two-pin jumper is
> fine) during reset.
>
> 3. An asynchronous logic-level serial Tx/Rx pair (i.e. serial port)
>
> On most of my boards, I include an FTDI232R chip which lets me control
> all those signals (and more) over USB, plus serve as a serial console
> when it's running. However, the standard E8a connector brings all
> those signals out anyway, so you could have one usb-based programmer
> for all your boards.
>
> I've also done live updates, using one MCU to update another, in my
> furnace controller - the gumstix board can reprogram any of the five
> R8C chips while the system is running. (most of the R8Cs have I2C,
> they make great "smart peripherals")
>