Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
???
01/10/08 18:11
Read: times


 		 #149252 - Not quite ...
Responding to: ???'s previous message
Brett said:
How can AC be set when the MSB of the lower nibble of ACC is set? It's not possible, so this case is not accounted for.

Not true. It's easy to have both AC and the MSB of the lower nibble set following an addition. For example:
Save This Code
    MOV	A,#0Ch
    ADD A,#0Ch
But this is not a valid BCD addition, so maybe we're still on the right track.

By the way, I just checked the data sheet for the C8051F120 and it doesn't say anything about its interpretation of DA A being anything other than biblical. So I think there's still an open question, even if it's just an issue with the SiLabs documentation.

-- Russ

PS: Are you Brett the apps guy from SiLabs?


List of 34 messages in thread
TopicAuthorDate
DAA Misunderstanding            01/01/70 00:00      
   could this be it?            01/01/70 00:00      
      Maybe ... nope            01/01/70 00:00      
   a double negative ???            01/01/70 00:00      
      ... or an exclusive OR            01/01/70 00:00      
      Case 4            01/01/70 00:00      
         Are there don't-care situations?            01/01/70 00:00      
            I think this is the case            01/01/70 00:00      
               Not quite ...            01/01/70 00:00      
                  no            01/01/70 00:00      
            True to bible            01/01/70 00:00      
   e-mail to SILabs sent just now            01/01/70 00:00      
   Operands must consist of two packed BCD digits!            01/01/70 00:00      
      OK, but what does a packed 07 look like            01/01/70 00:00      
         Correct            01/01/70 00:00      
            if case 4 is a biblical catastrophe            01/01/70 00:00      
               Not true            01/01/70 00:00      
                  more to this            01/01/70 00:00      
                     Same as Case 1            01/01/70 00:00      
   reply from SILabs            01/01/70 00:00      
      I'm happy now            01/01/70 00:00      
      I am willing to try...            01/01/70 00:00      
         DA A test program            01/01/70 00:00      
            the results...            01/01/70 00:00      
               DS89C450 is strictly "biblical", too...            01/01/70 00:00      
                  The DAA instruction is so specific...            01/01/70 00:00      
                     point of view            01/01/70 00:00      
                        Agreed!            01/01/70 00:00      
               the last hope gone... XC866 is DAA-biblical too            01/01/70 00:00      
                  no "pick and choose" eitherThe Bible or "the bible            01/01/70 00:00      
                     don't take it too literally, please...            01/01/70 00:00      
      DAA on other Architectures            01/01/70 00:00      
         this is how it happened            01/01/70 00:00      
         Thanks for the link!            01/01/70 00:00      

Back to Subject List