8 bit unsigned vs signed

[DarkKobold]

Hi all.
I believe that by using the char identifier, I can use it as an unsigned 8 bit integer. (I may be wrong). I am trying to use it for time, a total of 3 minutes, which is 180 seconds. (obviously) However, if I use an algorithm to decode the individual numbers, such as
min = 0;
tensec = 0;
//get x
if ((x - 60) > 0)
{
x -= 60;
min++;
}
if ((x - 10) > 0)
{
tensec++;
}
sec = x;

will the negation require it to convert to 16 bit math, therefore requiring more overhead?

[dvsoft]

Bonjour

int8 Value,Minute,Seconde;

Value = getc();
Minute = Value / 60;
Seconde = Value % 60;

Bonne journée

[Mark]

There is a little problem with your routine. You should use a loop:

[Neutone]

[DarkKobold]

Thank you for all of your help - I am still a tad confused. Will this guarentee to stay an 8 bit number? can you have an 8 bit number ranged 255-0 in PICC?

[Mark]

x-60 will always be greater than 0 unless x=60. The reason for this is since there is no sign bit, numbers cannot be < 0 only >= 0. If x=0 and you subtract 1 from it, x will now equal 255. Hope this clears it up for you.

[PCM programmer]