delay with variable

[Christoph]

hello!

i´m shure it is very simple, but:

why it is not the same?

"delay_ms(1000);"

AND

"
int X;
X=1000;
delay_ms(X);
"

with the first statement the delay is exactly 1second,
but with the second one it is much lower... why?

thanks in advance, christoph

[treitmey]

The first is using 1000
the second uses a 1000 stored in a 8 bit variable.
8 bit can at max hold 255.
so
1000=0x3E8 only the E8 is stored
thus e8=232
you get 232mS


CCS int is by default and int8

[Christoph]

okay, i see...

should it work with an int16?

[treitmey]

To find the biggest number a variable can hold take 2^n
to 2^16 = 65535 BUT
delay_ms will take an int8 variable.
Thought to look it up after I pressed submit.
edited...
Look to the link of PCM below. It shows the delay_ms inside a wrapper
that executes it multi times and DOES take the int16 variable.

[PCM programmer]

The delay_ms() function only accepts an 8-bit value when the parameter
is a variable. It can accept a 16-bit constant. To use a 16-bit variable
you need to use a loop. See this thread for an example function:
http://www.ccsinfo.com/forum/viewtopic.php?t=375

[Christoph]

thank you...

i understand.
but when i´m using int16 it´s also not working.

the delay is still not 1 sec...

[Christoph]

thank you guys...

i will try!

[Guest]