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Hi, I have just started using your uvision2. I received your tool when I bought the phillips development system. Here's my problem: I am targeting a philips 764 controller, this is a 8051 compatible, all code was written in assembly language. When I go to build an existing file which used the 'b' register I get the following error error A48: DATA-ADDRESS EXPECTED the line of the code it is issuing this error for is below clr b Thanks, John
WOW. I don't have a clue how I managed to do that. Here's what was in my reply message box when I clicked "Post". The CLR instruction only works for the accumulator, the carry flag, or any directly addressable bit. The accumulator is the only byte that can be cleared using this instruction. To clear register B you can use:
MOV B,#0
Thanks Dan. I have been using a different assembler which evidentally allows the CLR instruction to be used on the B register. John
I have been using a different assembler which evidentally allows the CLR instruction to be used on the B register. WOW. What does it encode that instruction as? Jon
Hi Jon, Regarding your question What does it encode that instruction as? That is CLR B Here you go I have been using the AVOCET SYSTEMS Assembler (AvCase), here's how it encoded the CLR B instuction CLR A E4 CLR B C2 F0 BTW CLR tr0 C2 8C CLR ea C2 AF Regards, John
IMHO I think your previous Avocet assembler had a serious problem. The produced code
CLR A E4 CLR B C2 F0 CLR tr0 C2 8C CLR ea C2 AF
Well, I don't profess to be an expert, and I'll run the sim again, but it's working in a prototype. I'll double check it regardless. Thanks, John
Just cos something's "working" doesn't mean to say that it's correct! It could be a pure fluke - maybe B just happens to only ever be set to 1 at that point in the code, so clearing bit 0 of B has the same effect as clearing B? Maybe the original programmer realised that only bit 0 was cleared, and was careful only ever to set set B to 0 or 1? Or maybe he was just plain lucky!?
Loet, You are correct. After running the Sim Bit 0 of the B register is being cleared not the entire B register. It did not impact the application because it is only used as temp storage for A while A is being used. Good Observation, John
I don't quite see the answer to the A48 error message. I get A48 when I changed myvar equ 002h to myvar: ds 1 Using v7.09
You posted your message into a thread that's been discussed to completion years ago, and you omitted just about all the necessary details for anyone to be able to really help you. So, back to square one: read the manual to learn what exactly that message means, and if you can't make heads or tails of it, show a complete example exhibiting the problem, not just a single line of code ripped entirely out of context.