I am going to use this little chip for the CPU of a tiny calculator. I've always wanted to build my own 4 function machine. The robot looks cool, but I don't think I have enough stuff to build one.
The PIC16C505 is a very tiny RISC microcontroller.
- operates at 1 MHz (or less depending on what you choose).
- 12 i/o pins
- CMOS device that can interface with TTL logic
- 1024 12-bit memory locations for program code
- 72 Bytes of SRAM
- 33 Instructions
Basically what I'm going to do is design a simple i/o subsystem and bus. The input will read what a user presses on a keypad and store the data to small registers. (2 numbers and an operation).
There will also be a small control chip (a Programmable Logic Array, or PAL) that will keep track of the state of the inputs. When the 2 numbers and operation are entered, the PAL will tell the PIC to read in the data from the i/o registers.
The PIC can be programmed in assembly, so I'll program it to read in data, do the appropriate operations, and then put the data on an output bus. This will drive the display bus.
I still have to draw all this out. But this is a preliminary plan.