How to rework "printf" function to use for two UARTS in the cygnal's MCU?

Instead of if (debug) clauses, try this:

#ifdef DBG
#    define debug
#else
#    define debug while (0)
#endif

// Usage: single line
debug printf("Got here\n");

// Usage: multiple line
debug
{
    g_errno = 12;
    printf("Got error, %d\n", g_errno);
}

Instead of if (debug) clauses, try this:

#ifdef DBG
#    define debug
#else
#    define debug while (0)
#endif

// Usage: single line
debug printf("Got here\n");

// Usage: multiple line
debug
{
    g_errno = 12;
    printf("Got error, %d\n", g_errno);
}

You may check this info.:

http://www.keil.com/support/docs/788.htm

Mark,

Yes, of course, that gives you compile-time control to produce an image which either has debug output or doesn't.

I needed the ability to enable/disable the debug output at run-time

In fact, I did also use conditional-compilation so that I could build either a completely "clean" (debug-free) image, or one with the runtime-controllable debug