Keil™, An ARM® Company

Technical Support

C51: 80C517A MA-STEP SHIFT BUG

QUESTION

I've heard there is a bug in the MA version of the 517A. If the 4 bit shift instruction (right or left) is used, one must wait 1 machine cycle before reading the result. I assume a simple NOP will suffice. Does the Keil toolset for the 8051 take this into consideration?

ANSWER

Yes. The C51 Library takes care of that. There is no need to modify anything in your program for this to work correctly.

Last Reviewed: Sunday, May 16, 2004


Did this article provide the answer you needed?
 
Yes
No
Not Sure