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Hi, Does anyone know how to convert a BINARY 8 bit to a 2 digit packed BCD. Example if I have value 0x0C (wich is 12 decimal) the result will be 12 or a char value of 0x12. thank you, Adi,
the above should be
unsigned char chartobcd(unsigned char ) { if (n >99) crash(); return ((n / 10) << 4) | (n % 10); }
Hi, WOW I'm learning from the PRO...your code seems very compact. I will try it. But will I get a packed BCD value ? I'll get back to you if I have some problems. Thank you, Adi,
Hi If a want to write a BCD number to a RTC, I prefear to do that check in the input routine, and that because of the different of input values. year = 00 - 99 month = 01 - 12 day = 01 - 31 hour = 0 - 23 min = 0 - 59 sec = 0 - 59 Ingvar
will I get a packed BCD value ? Yes, by "ORing" the two halves of the number together, you get a single byte, two digit BCD number.
And now the add-on question for extra points: how many assembly instructions is the minimum this functionality can be achieved in? You may assume all inputs are already in the correct registers, and it doesn't matter where the output is, as long as it's somewhere.
But what is the more interesting value - the number of assembly instructions or code efficiency? A DIV and MODULO takes very long, so it might be better to use some add-and-compare loops Jochen
A DIV and MODULO takes very long, Indeed. And it's too many instructions, anyway ;-) So sorry, but no cigar yet.
if (n >99) crash(); The above line (or something akin to it) is used thousands of times in all Microsoft products. They of course document better so their equivalent would be.
/* Randomly screw the customer so they purchase an upgrade. *. if (user_is_doing_something_important) { crash_horribly_and_do_not_save(); }