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1. Serial Wire Output: <\/h2>\n\n\n\n
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Serial Wire Output (SWO) alongside Serial Wire Debug (SWD) allows for the CPU to emit real-time trace data. In particular, when used with an Instrumentation Trace Macrocell (ITM), it can be used to form a Serial Wire Viewer (SWV). The ITM ports are provided by the ARM controller. The SWV typically implements a form of <\/p>\n\n\n\n After we created a new header file with name of swo.h, we can implementing the functions such as:<\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n In Keil uVision, the printf function can be retargeted as following:<\/p>\n\n\n\n For the other functions:<\/p>\n\n\n\n <\/p>\n\n\n\n In STM32CubeIDE, the printf functionality can be retargeted as following:<\/p>\n\n\n\n <\/p>\n\n\n\n After you compile the code and enter a debug session:<\/p>\n\n\n\n <\/p>\n\n\n\n Please check the video from here:<\/p>\n\n\n\nprintf<\/code> style debugging for embedded systems.<\/p>\n\n\n\n2. Implementing header file:<\/h2>\n\n\n\n
#ifndef __SWO__h\n#define __SWO__h\n#include <stdio.h>\n#include "stm32f4xx.h" \/\/ Device header\n\nvoid log_error(char *p);\nvoid log_info(char *p);\nvoid log_debug(char *p);\nvoid log_debug_array(char const * const label, void const *array, uint16_t const len);\n#endif<\/pre><\/div>\n\n\n\n
3. Implementing source code for keil uVision:<\/h2>\n\n\n\n
struct __FILE {int handle;\/* Add whatever you need here *\/};\n\nFILE __stdout;\nFILE __stdin;\n\nint fputc(int ch, FILE *f)\n{\n ITM_SendChar(ch);\n return(ch);\n}<\/pre><\/div>\n\n\n\nvoid log_error(char *p)\n{\n\n\tprintf("log Error: ");\n\n\t\tprintf((char*)p);\nprintf("\\r\\n");\n\n\n}\n\nvoid log_info(char *p)\n{\n\n\tprintf("log info: ");\n\n\t\tprintf((char*)p);\nprintf("\\r\\n");\n\n\n}\n\nvoid log_debug(char *p)\n{\n\n\tprintf("log debug: ");\n\n\t\tprintf((char*)p);\nprintf("\\r\\n");\n\n\n}\n\nvoid log_debug_array(char const * const label, void const *array, uint16_t const len)\n{\n \tprintf("log debug array: ");\n \n for (uint16_t i = 0; i < len; i++)\n {\n \tuint8_t val = *((uint8_t *)(array + i));\n \tprintf("0x%02X", val);\n \t\n \t\/\/ Add ", " after all elements except the last one.\n \tif (i < len - 1)\n \t{\n \t printf(", ");\n \t}\n }\n\tprintf("}\\n");\n}<\/pre><\/div>\n\n\n\n4. Implementing source code for STM32CubeIDE:<\/h2>\n\n\n\n
int __io_putchar(int ch)\n\t{\n\t ITM_SendChar(ch);\n\treturn ch;\n\t}\n\n<\/pre><\/div>\n\n\n\n5. Setup Serial Wire Viewer in Keil uVison:<\/h2>\n\n\n\n
![\"\"](\"https:\/\/blog.embeddedexpert.io\/wp-content\/uploads\/2022\/03\/Screen-Shot-2022-03-04-at-7.18.43-AM-1024x585.png\")
<\/figure>\n\n\n\n![\"\"](\"https:\/\/blog.embeddedexpert.io\/wp-content\/uploads\/2022\/03\/Screen-Shot-2022-03-04-at-7.26.49-AM-1024x585.png\")
<\/figure>\n\n\n\n6. Setup for STM32CubeIDE:<\/h2>\n\n\n\n