[参考译文] LP-MSPM0L2228：无法使用 CCS 20.0.1.4__1.6.1使用 printf ()来打印变量

尊敬的 Helic：

对我来说,这是一件好事。 但我对输出接口有疑问。 printf()的默认输出是 UART0、我是否知道如何将其更改为 CIO？

谢谢！

Edware

您好、 Edware

有关 UART 接口更改、请参阅演示注释。

 * @Tips:
 * You can modify the hardware of MSPM0 in printf.c file, Line 132:
 * Function: static inline void _putchar(const char _c).
 * You can use the macro definitions in printf.h to turn off
 * complex printf functions such as float point numbers,
 * longlong type variables, to reduce the program size.

此致、

Helic

尊敬的 Helic：

谢谢你。 我知道我可以修改_putchar()函数。

static inline void _putchar (const char _c)｛

但我不知道 CIO 的实例。 是否有向 CIO 输出消息的示例？

谢谢！

Edware

您好、 Edware

您可以在 ticlang 中找到一些相关代码、例如 fputs.c、如下所示：
此器件函数会将 CIO 输出作业发送到 CCS 控制台。

/*****************************************************************************/
/* FPUTS -  Write a string to a stream                                       */
/*                                                                           */
/*    This function writes string _PTR to stream _FP, returning the number   */
/*    of characters written upon success, or an EOF upon failure.            */
/*                                                                           */
/*****************************************************************************/
_CODE_ACCESS int fputs(const char * __restrict _ptr, FILE * __restrict _fp)
{
   /*------------------------------------------------------------------------*/
   /* Local variables                                                        */
   /*------------------------------------------------------------------------*/
   size_t   num_left, ptr_strlen;
   char     *fpos          = (char *)_ptr;
   int      room_left,
            flush_flag     = 0,
            num_to_write;

   /*------------------------------------------------------------------------*/
   /* The current thread in a multi-threaded application must protect access */
   /* to the file stream. In this case, _fp may be updated, so we must       */
   /* ensure that the local copy of _fp is flushed to shared memory before   */
   /* leaving the critical section (invalidated if it is not modified).      */
   /*------------------------------------------------------------------------*/
   __TI_file_lock(_fp);

   /*------------------------------------------------------------------------*/
   /* Make sure that the stream is writeable.                                */
   /*------------------------------------------------------------------------*/
   if (!__TI_wrt_ok(_fp)) 
   { 
      __TI_data_synch_INV(_fp, sizeof(FILE));
      __TI_file_unlock(_fp);
      return (EOF);
   }
 
   room_left = (int)(_fp->bufend - _fp->pos);
   ptr_strlen = num_left = strlen(_ptr);

   /*------------------------------------------------------------------------*/
   /* If the stream is non-buffered, call the lowlevel WRITE function.       */
   /*------------------------------------------------------------------------*/
   if (_BUFFMODE(_fp) == _IONBF) 
   {
       int num_written = 0;

       while (num_left > 0)
       {
	   int write_return = write(_fp->fd, _ptr + num_written, num_left);
	   if (write_return < 0) 
	   { 
	       _SET(_fp, _STATERR); 
               __TI_data_synch_WBINV(_fp, sizeof(FILE));
               __TI_file_unlock(_fp);
	       return (EOF);
	   }
	   else
	   {
	       num_written += write_return;
	       num_left    -= write_return;
	   }
       }

       __TI_data_synch_WBINV(_fp, sizeof(FILE));
       __TI_file_unlock(_fp);
       return ptr_strlen;
   }
 
   /*------------------------------------------------------------------------*/
   /* Write the string into the buffer, flushing it when full.               */
   /*------------------------------------------------------------------------*/
   while (num_left > 0)
   {
      num_to_write = (num_left > room_left) ? room_left : num_left;
      if ((_BUFFMODE(_fp) == _IOLBF) && memchr(fpos, '\n', num_to_write))
      { 
         num_to_write = (char *)memchr(fpos, '\n', num_to_write) - fpos + 1;
         flush_flag = 1;
      }
      memcpy(_fp->pos, fpos, num_to_write);

      /*---------------------------------------------------------------------*/
      /* Update pointers and counters.                                       */
      /*---------------------------------------------------------------------*/
      _fp->pos  += num_to_write;
      fpos      += num_to_write;
      num_left  -= num_to_write;
      room_left -= num_to_write;

      /*---------------------------------------------------------------------*/
      /* If the buffer is full, flush it.  Any I/O errors cause this         */
      /* function to exit, returning an EOF.                                 */
      /*---------------------------------------------------------------------*/
      if (room_left == 0 || flush_flag)
      {
         if (__TI_doflush(_fp))
         {
            _SET(_fp, _STATERR);
            __TI_data_synch_WBINV(_fp, sizeof(FILE));
            __TI_file_unlock(_fp);
            return (EOF);
         }
         room_left = (int)(_fp->bufend - _fp->pos);
         _SET(_fp, _MODEW);
         flush_flag = 0;
      }
   }

   __TI_data_synch_WBINV(_fp, sizeof(FILE));
   __TI_file_unlock(_fp);
   return ptr_strlen;
}

但我从来没有尝试将 tinyprintf 与 CIO 合并。

此致、

Helic