Search found 5 matches

by lenkki
Wed Dec 17, 2008 3:33 pm
Forum: Programming
Topic: 65816 Addressing modes and cycle counts.
Replies: 14
Views: 8972

I would love to try my hands on a real 65816 but I don't have the hardware. I'm trying to emulate one you see.
by lenkki
Mon Dec 15, 2008 12:27 pm
Forum: Programming
Topic: 65816 Addressing modes and cycle counts.
Replies: 14
Views: 8972

TMorita's and dclxvi's posts are contradicting. I interpret TMorita's post such that my assumption would hold but dclxvi's post states that it will not allways hold. Which is it ? :)
by lenkki
Sat Dec 13, 2008 11:20 am
Forum: Programming
Topic: 65816 Addressing modes and cycle counts.
Replies: 14
Views: 8972

Ok I've solved all issues I had except for a few which I have based upon assumptions that emulation mode will indeed behave like a fixed 6502.

For example Absolute indexed modes will not cross bank boundaries as they can do in native mode.

In general is it a fair assumption that no addressing ...
by lenkki
Fri Dec 12, 2008 1:08 pm
Forum: Programming
Topic: 65816 Addressing modes and cycle counts.
Replies: 14
Views: 8972

So if I understood the programmers manual correctly, when using the DP,X in emulation mode the address would be

EA = (0x00DHDL + (offset + X)0xFF ) & 0x00FFFF

And in native mode

EA = (0x00DHDL + offset + X ) & 0x00FFFF

(X 8/16 bit as per the X flag)

And in general with the emulation flag as a ...
by lenkki
Fri Dec 12, 2008 1:25 am
Forum: Programming
Topic: 65816 Addressing modes and cycle counts.
Replies: 14
Views: 8972

65816 Addressing modes and cycle counts.

I have a few questions about the addressing modes of the 65816 MCU.

1) Is there any difference in the operation between the following modes:
E=1, X=1, M=1 and E=0, X=1, M=1 ?

2) I understand that I can move the "zero-page" to a arbitrary location even in Emulation mode.
Say that I have D = 0x1080 ...