I need the datasheet or info about the CPU HD62002A03. This chip is the CPU of a Casio calculator model fx-880P. The manufacturer is Hitachi but... nothing in Google about this CPU.
I would imagine it's a mask programmed chip, specifically made for Casio, so there won't be a datasheet - you 'may' be able to find the generic chip it's based on, but you will have to try and extrapolate from the number on the Casio chip. But even if you can find one?, I wouldn't have thought it would be much help, as 'presumably' it has pre-programmed ROM inside?.
CPU: Hitachi HD62002A03 at 1.228 MHz
RAM: 32 KB (external chip)
ROM: 32 KB (external chip). Optional: expansion pack of 32 KB.
LCD drivers: 2 x HD66100F (I have the datasheet: lcd driver with 80 channels/outs).
Probably the interpreter of BASIC is integrated in the CPU... and in the external ROM only the software libraries...
CPU: Hitachi HD62002A03 at 1.228 MHz
RAM: 32 KB (external chip)
ROM: 32 KB (external chip). Optional: expansion pack of 32 KB.
LCD drivers: 2 x HD66100F (I have the datasheet: lcd driver with 80 channels/outs).
Probably the interpreter of BASIC is integrated in the CPU... and in the external ROM only the software libraries...
I don't think you have shown any evidence for your hypothesis. Even if you knew something about the processor you would have a complete lack of tools for doing anything with it.
Any programmers out there who have ever written a program for this processor please clap your hands...?....?