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Rewriting putchar() on MSP430F149

Started by Unknown January 14, 2005
I think, that only reasonable way to make terminal connection between
MSP430F149 <-> PC, is to rewrite low-level fuction putchar() to use
USART and let upper-level functions like printf() to make all the
conversions needed.
I'm using IAR and/or mspgcc. How do I replace putchar.o in library
files needed, and what are those lib-files in both systems?

ispe@luukku.com wrote:
> I think, that only reasonable way to make terminal connection between > MSP430F149 <-> PC, is to rewrite low-level fuction putchar() to use > USART and let upper-level functions like printf() to make all the > conversions needed. > I'm using IAR and/or mspgcc. How do I replace putchar.o in library > files needed, and what are those lib-files in both systems? >
I use uprintf() which sends output one character at a time to a designated function. In my case the designated function is one I wrote myself and contains low level code to push characters out through the UART. I have this function in my program so it is not a library as such. My print statements look like this: uprintf(my_designated_function, "Hello world" ); Let me know if you would like more detail. Regards JC
ispe@luukku.com wrote:

> I think, that only reasonable way to make terminal connection > between MSP430F149 <-> PC, is to rewrite low-level fuction putchar() > to use USART and let upper-level functions like printf() to make all > the conversions needed. > I'm using IAR and/or mspgcc. How do I replace putchar.o in library > files needed, and what are those lib-files in both systems?
With IAR putchar() calls some function _cantrember(), IIRC. This function can be declared anywhere in your project. It must be somewhere in the IAR help. I don't have IAR at home, but I will look it up at work tomorrow (if I don't forget ;-) /Jan-Hinnerk
It is quite easy, and documented in the configuration section of the C
compiler reference manual.  The putchar() function calls
__low_level_put() into which you put your serial transmit function
call.  In my case:

static void __low_level_put( int Character )
{
USART_0_TX_Char( (unsigned char) Character ) ;
}

IAR have an app note on the web site that covers the use of the serial
port quite comprehensively and includes the implementation of a
buffered, interrupt driven serial interface.

Ian


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