Mike,
Thanks for the idea!
If I understand the data sheet, I'd still have to do the work of separating the hundreds, tens and ones digits and then send them serially to the SAA1064. Using the PIC to drive the LED, the digit separation is the only real work I have to do. Multiplexing in the PIC is pretty simple really. It only requires writing the digit segment masks to a port and latching/unlatching one of three output pins in a "round robin" fashion for the three common cathodes. With the SSA1064, I'd still be multiplexing in a way because I'd have to send each digit in sequence serially, also in a "round robin" fashion. To display a value on a 7-segment LED directly from a PIC, I simply get the segment bitmask as a single byte from a jump table and write it to the port. That part couldn't get any simpler or quicker. Staying with the PIC to drive the LED has other advantages as well by keeping the parts count down and the schematic simpler.
Do you happen to have any PIC assembler code that interfaces with the SAA1064? Specifically the "static mode". Using it that way might only require streaming data to it when a value changes rather than continually. I'd like to take a look at an example to see how it works. If it does make things easier than what I have, I'd be interested for sure.
Thanks again,
Dave