View source for Design of sxgo

This page describes the main design ideas behind sxgo. The implementation of this microcontroller emulator revolves around a few main ideas:
* separation of instruction decoder and instruction implementation
* a meta-programmed list of instructions
* using metaprogramming to create a fast instruction decoder
* precompilation of instructions into 'function pointers'. Actually these would also contain bound arguments (in a similar way to boost.bind).
==Instruction Implementation==
The idea is to have one class that consists of an SX 'state' (ram, rom, special registers, program counter) and that implements the instruction set. See the snippet below:

<source lang="cpp">
struct sx_controller_impl 
{
    // snip...
    // note that this is simplified source code, this does not set any 
    // flags yet.
    void execute( const clr_fr &, int arg_register)
    {
    	ram( arg_register) = 0;
    }

    void execute( const clr_w &)
    {
    	w = 0;
    }

    void execute( const mov_w_not_fr &, int arg_register)
    {
    	w = ~ram( arg_register);
    }

    // etc...
};
</source>