I've thought about that. Few low-cost MCU's are capable of the required bit rate, and contain the requisite amount of code memory, though.

It's really simple to get around the programming hurdle ... one programs the parts, installs them in the application circuit, where they reside more or less alone, since it plugs into another application circuit, then uses them as needed, under the control of an external reset signal. OTP's would work, I believe.


There are "issues" with using MCU's, starting with the bit rate. Since this is something potentially to be shipped with each product, cost is an issue.

Aside from the problem that "standard" XILINX tools don't do the job on their own, the XC18Vxx parts could do the job, requiring only that they be powered, clocked, and nCS grounded. Apparently, they'll do that until a DONE control goes positive. That would appear to be adequate, though their clock rate tops out at 33 MHz. They do have a dedicated set of JTAG pins for programming, though. I've got a supply of 4Mbit TQFP-44 parts, and they're a bit less than 1/2" square, overall. They'd work if I knew how to load them with what I want. A little reading should settle that, though I suspect that there's something more modestly priced.



This is still very preliminary, but I now have several candidates, thanks to the suggestions provided by you, and others.

Ramtron's SPI parts could be made to work, since they have the requisite clock rate and could, with the aid of an SPLD, be urged to perform the necessary function, since all they require is a command and a starting address.

I imagine I'll come up with a minimal solution. What I like about the XILINX parts is that they require only a clock and a reset, allowing one to use only one external control to halt the process. The target application doesn't really require reprogrammability. THe thing I don't like, though is that they're not 5-volt parts.

RE