6502.org Forum  Projects  Code  Documents  Tools  Forum
It is currently Sun Nov 10, 2024 7:48 pm

All times are UTC




Post new topic Reply to topic  [ 1 post ] 
Author Message
PostPosted: Sat Jul 19, 2008 2:27 am 
Offline

Joined: Tue Dec 25, 2007 4:57 am
Posts: 109
It is nice to have 65816 MPU when ORA, AND, EOR, ADC, STA, LDA, CMP, and SBC instructions have Long Absolute Address and Long Absolute Address Index on $XF.

I wonder why the designer of 65816 MPU decided not to put Long Absolute Address on ASL, ROL, LSR, ROR, INC, and DEC because they might do not have enough 8-bit instruction available. All of them are
R-M-W.

It is annoying when I want R-M-W instructions to modify data outside of bank $00. It is the only way is to push bank $00 into stack and sets new bank to data bank register and then pulls it out of stack. Now, bank $01, $02, ...etc can work to use R-M-W instructions.

Do you have example code how R-M-W instructions can be used to all 256 banks without using Long Absolute Address? I hate to push and pull data into and from stack.

Bryan Parkoff


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC


Who is online

Users browsing this forum: Google [Bot] and 7 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: