Printf statement used on IAR compiler / MSP430 processor

On 2007-10-05, JS <xyz@yahoo.com> wrote:

>> printf isn't too useful On the ones with 2K of codespace and
>> 128-256 bytes of RAM. On ones with 60KB of codespace and 4K of
>> RAM, it can be very useful.  Since I rarely have a spare HW
>> UART, I ususally bit-bang the printf output.  I also use a
>> carefully optimized, custom printf function that's only a
>> couple KB of code and requires very little RAM.

> One of the basic example which I think it is quite useful is
> for instance if you want to find out what the output pins
> of  PORT1  are at certain point in the program --- that way
> you don't have to physically put the scope probe on them.
>
> void read_port_value(void)
> {
>    uchar value;
>    value = PORT1;       //read  CPU port1
>    printf(" Display Port1 value = %X", value);      //Display port1 in hex 
> on PC terminal
> }

Which is fine if you've got the spare RAM and ROM for printf.
On some of my projects I've only got a few bytes of extra RAM,
and printf just can't run with that little available RAM for it
to use.

-- 
Grant Edwards                   grante             Yow!  In Newark the
                                  at               laundromats are open 24
                               visi.com            hours a day!

On Oct 4, 8:45 pm, "JS" <x...@yahoo.com> wrote:
> One of the basic example which I think it is quite useful is
> for instance if you want to find out what the output pins
> of  PORT1  are at certain point in the program --- that way

It really depends if you want to pull in all that extra baggage.

Converting an 8-bit value to ASCII hex is a few lines of C or
assembler, and it doesn't require any RAM [on most architectures I can
think of]; it can be done entirely in registers.