Bit manipulation: R65c02 and W65c02

dlenmn · Post by **dlenmn** » Sat Jan 14, 2006 7:58 pm

I was looking at WDC's W65c02 data sheet (http://www.westerndesigncenter.com/wdc/ ... 65c02s.pdf) and noticed that it listed Reset Memory Bit (RMB), Set Memory Bit (SMB), Branch on Bit Reset (BBR), and Branch on Bit Set (BBS) as instructions. However, appendix c of WDC's programming manual (http://www.westerndesigncenter.com/wdc/ ... manual.pdf) indicates that these instructions are only available to Rockwell's R65c02. Being able to test any bit in any byte in the zero page sounds like a nice feature. Do WDC's chips these instructions or not?

GARTHWILSON · Post by **GARTHWILSON** » Sat Jan 14, 2006 9:57 pm

Yes, all of WDC's 65c02's today have these instructions. Originally only Rockwell had them, but for the last several years, all WDC ones have had them too. They started before year 2000 IIRC.

dlenmn · Post by **dlenmn** » Sat Jan 14, 2006 10:04 pm

Score. Thanks for the confirmation.

kc5tja · Post by **kc5tja** » Sat Jan 14, 2006 10:20 pm

dlenmn wrote:

Score. Thanks for the confirmation.

However, these instructions are NOT in the 65C816 instruction set, even when running in 6502-mode. (For the benefit of anyone reading this thread for informational purposes.)