Lpc2000

My question is:
In order to have the printf function properly working, What do I have 
to do?
- Do I have to include the stdio.h file?
- Do I have to define a putchar function?
- If printf() uses putchar(), does the putchar() included in the 
compiler? Do I have to provide it?

So, what are the steps in order to use the serial with printf()? 
(assumming I already have the serial initialised and working with the 
putchar routine...)

Thanks

--- In lpc2000@yahoogroups.com, "Gus" <gus_is_working@y...> wrote:
> 
> what is printf expecting back from putchar?
> what is the return value of your printf? if printf is returning 
> number less than the character count then printf is not likeing the 
> return value from putchar()
> 
> 
> Gus
> 
> --- In lpc2000@yahoogroups.com, "gustavo_sagasti" 
> <gustavo_sagasti@y...> wrote:
> > 
> > Hi:
> > I 'm working with Keil and GNU Compiler, and I try to use the 
> printf 
> > function. I initialised the UART0 and the putchar function works 
> > fine. But the printf doesn't work. It only works if I use it as 
> printf
> > ("H"), but if I use printf("Hello"), it doesn't work.
> > 
> > This is the putchar function...
> > 
> > int putchar(int ch)  {                  /* Write character to 
> Serial 
> > Port    */
> > 
> >   if (ch == '\n')  {
> >     while (!(U0LSR & 0x20));
> >     U0THR = CR;                      /* output CR */
> >   }
> >   while (!(U0LSR & 0x20));
> >   return (U0THR = ch);
> > }
> > I also include the stdio.h library. Do I have to include 
something 
> > else to have the printf function working correctly?
> > 
> > Thanks