Interesting, but what can you use it for. It's max operating frequency is 800KHz and you must control it with an external MCU.

So here's the question: You would have to parse and translate the calculations you wish performed into bytes and into Reverse Polish Notation and order the bytes after maybe converting the values you have from floating point variables. You then have to transfer (maybe 8-bytes of data plus instructions) and transfer them byte by byte to the math coprocessor and also send it the instructions for the operation to be performed. When the processor is finished calculating, you would have to transfer the 8 or so byte result to your MCU and re-assemble the result into a float or integer or whatever to do the next calculation and repeat this process.

But with a modern PICC chip, for instance, say operating at 32MHz and programmed with C-language, at the same price or for free for a sample chip, but you could perform all these calculations in much less time than this co-processor and no have to work with RPN communication.

Although you would use up quite a bit of program memory on the PICC, it takes certainly many k of code to do some MCU computing at a high math level, and also takes some computing time to accomplish calculations, but you get the result you want in 24-bit or 32 bit accuracy.

But your PCB real estate would be much less used up in supporting this chip which is not really TTL compatible with its signaling and control lines and clock, etc.

So what's the point of going to all this trouble to maybe get less using more time and money? If you wanted a sci-calculator you could buy one for a few bucks these days at your local discount store.

Everyone should have a hobby.