topic Re: Inc size for BCHG #6, (A2)+ in ColdFire/68K Microcontrollers and Processors

Inc size for BCHG #6, (A2)+

tupdegrove — Sun, 12 Jul 2009 01:56:17 GMT

Test M[a2].[6]

I know this is a byte operation but is register a2 post incremented by 1 or 4 bytes?

Tim

Re: Inc size for BCHG #6, (A2)+

kef — Sun, 12 Jul 2009 14:33:57 GMT

What's this: Test M[a2].[6] ?

All (Ax)+ like operations will increment Ax by sizeof of operand. Sizeof is 1 in your case (BCHG.B), and A2 will be incremented by 1.

Re: Inc size for BCHG #6, (A2)+

tupdegrove — Mon, 13 Jul 2009 21:21:48 GMT

Thanks Kef. Got it. An inc by 1 makes sense if mem[a2] just represents an 8-bit value. However, I would think the more common case on a 32-bit cpu would be to inc by 4 because mem[a2] is the ls byte of a 32-bit value.

Tim