Paz Schmidt, Alejandro

6809 and 6309 Compatible core

Though JMP indexed instruction such as JMP ,X is not working, I fixed this issue.

JMP indexed not working

I have debugged IRQ/FIRQ behaviors as this IP does not support IRQ/FIRQ functionarities.
I also added HALTREQ/HALTACK functionarities.

IRQ/FIRQ not working

Extended addressing mode JSR does not seem to do much of anything. :-(

I guess it's hard to check so many different operations and modes.

Bob Grieb

BD xx xx not working

STX instruction is also not working.   BF xx xx    So I guess there may be 
a bunch of op codes that don't work.   :-(

Bob Grieb

BF xx xx not working

This op code:  FD 1C 08	   std	X1C08  

does not seem to work.  FD is the opcode, the
other two bytes are the address to which the D 
accumulators are supposed to be stored, but   
It doesn't cause a write to memory to occur. 

Thanks,

      Bob Grieb

FD xx xx opcode

The 6809 has an op-code for negate with carry. Once I needed it and found it. It sits at the expected F/E position when you look at negate, subtract and subtract with carry and do a rectangle using the three known op-codes.

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6809 and 6309 Compatible core