J-link RTT Viewer - 技术栈

背景：最近解决升级异常的问题，BMS的板子没有留多余的debug串口，只有jlink烧录口。jlink debug了一次，没有进入断点，不方便。升级是概率性的失败，还是习惯串口打印的方式排查，之前看到过这个RTT(Real-Time Transfer)的调试方式，今天就试试。（以后没有预留串口，心里也不慌了）

把jlink的SWD接口，当做debug串口使用，达到和串口使用printf一样的效果，没有实测效率，据说比串口printf耗时更低。

1.在工程里面加文件：

SEGGER_RTT.c

SEGGER_RTT_printf.c

SEGGER_RTT_Conf.h

SEGGER_RTT.h

2.文件的来源

我的在 C:\Program Files\SEGGER\JLink\Samples\RTT\SEGGER_RTT_V798a.zip

这个压缩包里面。

3.使用

最好使用前调用初始化函数

SEGGER_RTT_Init();

再调用输出函数，和printf使用类似：

SEGGER_RTT_printf(0, "\r\n");

4.样例：

c 复制代码

/*********************************************************************
*                    SEGGER Microcontroller GmbH                     *
*                        The Embedded Experts                        *
**********************************************************************
*                                                                    *
*            (c) 1995 - 2021 SEGGER Microcontroller GmbH             *
*                                                                    *
*       www.segger.com     Support: support@segger.com               *
*                                                                    *
**********************************************************************
*                                                                    *
*       SEGGER RTT * Real Time Transfer for embedded targets         *
*                                                                    *                                                                 *
**********************************************************************
*                                                                    *
*       RTT version: 7.98a                                           *
*                                                                    *
**********************************************************************

--------- END-OF-HEADER --------------------------------------------
File    : Main_RTT_MenuApp.c
Purpose : Sample application to demonstrate RTT bi-directional functionality
*/

#define MAIN_C

#include <stdio.h>

#include "SEGGER_RTT.h"

volatile int _Cnt;

/*********************************************************************
*
*       main
*/
void main(void) {

  SEGGER_RTT_ConfigUpBuffer(0, NULL, NULL, 0, SEGGER_RTT_MODE_BLOCK_IF_FIFO_FULL);

  SEGGER_RTT_WriteString(0, "SEGGER Real-Time-Terminal Sample\r\n\r\n");
  SEGGER_RTT_WriteString(0, "###### Testing SEGGER_printf() ######\r\n");

  SEGGER_RTT_printf(0, "printf Test: %%c,         'S' : %c.\r\n", 'S');
  SEGGER_RTT_printf(0, "printf Test: %%5c,        'E' : %5c.\r\n", 'E');
  SEGGER_RTT_printf(0, "printf Test: %%-5c,       'G' : %-5c.\r\n", 'G');
  SEGGER_RTT_printf(0, "printf Test: %%5.3c,      'G' : %-5c.\r\n", 'G');
  SEGGER_RTT_printf(0, "printf Test: %%.3c,       'E' : %-5c.\r\n", 'E');
  SEGGER_RTT_printf(0, "printf Test: %%c,         'R' : %c.\r\n", 'R');

  SEGGER_RTT_printf(0, "printf Test: %%s,      \"RTT\" : %s.\r\n", "RTT");
  SEGGER_RTT_printf(0, "printf Test: %%s, \"RTT\\r\\nRocks.\" : %s.\r\n", "RTT\r\nRocks.");

  SEGGER_RTT_printf(0, "printf Test: %%u,       12345 : %u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%+u,      12345 : %+u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%.3u,     12345 : %.3u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%.6u,     12345 : %.6u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%6.3u,    12345 : %6.3u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%8.6u,    12345 : %8.6u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%08u,     12345 : %08u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%08.6u,   12345 : %08.6u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%0u,      12345 : %0u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%-.6u,    12345 : %-.6u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%-6.3u,   12345 : %-6.3u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%-8.6u,   12345 : %-8.6u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%-08u,    12345 : %-08u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%-08.6u,  12345 : %-08.6u.\r\n", 12345);
  SEGGER_RTT_printf(0, "printf Test: %%-0u,     12345 : %-0u.\r\n", 12345);

  SEGGER_RTT_printf(0, "printf Test: %%u,      -12345 : %u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%+u,     -12345 : %+u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%.3u,    -12345 : %.3u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%.6u,    -12345 : %.6u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%6.3u,   -12345 : %6.3u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%8.6u,   -12345 : %8.6u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%08u,    -12345 : %08u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%08.6u,  -12345 : %08.6u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%0u,     -12345 : %0u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-.6u,   -12345 : %-.6u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-6.3u,  -12345 : %-6.3u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-8.6u,  -12345 : %-8.6u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-08u,   -12345 : %-08u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-08.6u, -12345 : %-08.6u.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-0u,    -12345 : %-0u.\r\n", -12345);

  SEGGER_RTT_printf(0, "printf Test: %%d,      -12345 : %d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%+d,     -12345 : %+d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%.3d,    -12345 : %.3d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%.6d,    -12345 : %.6d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%6.3d,   -12345 : %6.3d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%8.6d,   -12345 : %8.6d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%08d,    -12345 : %08d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%08.6d,  -12345 : %08.6d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%0d,     -12345 : %0d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-.6d,   -12345 : %-.6d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-6.3d,  -12345 : %-6.3d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-8.6d,  -12345 : %-8.6d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-08d,   -12345 : %-08d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-08.6d, -12345 : %-08.6d.\r\n", -12345);
  SEGGER_RTT_printf(0, "printf Test: %%-0d,    -12345 : %-0d.\r\n", -12345);

  SEGGER_RTT_printf(0, "printf Test: %%x,      0x1234ABC : %x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%+x,     0x1234ABC : %+x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%.3x,    0x1234ABC : %.3x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%.6x,    0x1234ABC : %.6x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%6.3x,   0x1234ABC : %6.3x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%8.6x,   0x1234ABC : %8.6x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%08x,    0x1234ABC : %08x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%08.6x,  0x1234ABC : %08.6x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%0x,     0x1234ABC : %0x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%-.6x,   0x1234ABC : %-.6x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%-6.3x,  0x1234ABC : %-6.3x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%-8.6x,  0x1234ABC : %-8.6x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%-08x,   0x1234ABC : %-08x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%-08.6x, 0x1234ABC : %-08.6x.\r\n", 0x1234ABC);
  SEGGER_RTT_printf(0, "printf Test: %%-0x,    0x1234ABC : %-0x.\r\n", 0x1234ABC);

  SEGGER_RTT_printf(0, "printf Test: %%p,      &_Cnt      : %p.\r\n", &_Cnt);

  SEGGER_RTT_WriteString(0, "###### SEGGER_printf() Tests done. ######\r\n");
  do {
    _Cnt++;
  } while (1);
}

/*************************** End of file ****************************/

实用：

c 复制代码

    {
        SEGGER_RTT_Init();
        SEGGER_RTT_printf(0, "EMS boot\r\n");

        SEGGER_RTT_WriteString(0, "###### Testing SEGGER_printf() ######\r\n");
        uint32_t tmp = 12;
        SEGGER_RTT_printf(0, "printf Test: %%u,         'S' : %c.\r\n", 'S');
        SEGGER_RTT_printf(0, "printf Test: %%u,       12345 : %u.\r\n", tmp);
    }

5.JlinkRTT viewer

点击File--->connect