Q:

Use microprocessor with arduino / ESP32 WROVER

I was looking through some of the atmel microprocessors, and I was wondering if you could use a microprocessor (say, the atsam91) as a coprocessor for a microcontroller (say, an esp32 wrover (240Mhz)), so if the microcontroller needed to do any processing-heavy arithmetic, it could simply send through the instructions to the ATSAM.  
Is this possible?  
And if so, how would the microcontroller send through the instructions and in what format?

A:

"how would the microcontroller send through the instructions and in what format?"  Simple way would be via serial communications.  Faster way would be via SPI communications, which most Arduino would support using 8 MHz clock rate, so it's pretty quick.
If you look at an MP3 player module as an example, that is what is basically going on. The Arduino is sending the MP3 processor the commands to play this track, that track, stop, pause, etc. The MP3 processor then accesses the SD card, reads the info, does the MP3 decompression, and turns it into audio to drive speakers.
Format, that has to be worked out for the information going back and forth.

