> For the complete documentation index, see [llms.txt](https://ykkim.gitbook.io/EC/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ykkim.gitbook.io/EC/ec-course/tutorial/mdk-uvision/debugging-in-uvision.md). # Debugging in uVision ## Overview In this tutorial, we will learn how to use uVision for debugging firmware programming. ## Preparation * Open your previous tutorial project or can create a new project. * You can also copy the given example "TU\_uVision\_Debugging.c" [source code here](https://github.com/ykkimhgu/EC-student/tree/main/tutorial/tutorial-student) * You will learn how to use debugging mode to check how the registers change ``` #include "stm32f4xx.h" #define LED_PIN 5 //LD2 #define BUTTON_PIN 13 void RCC_HSI_init(void); //defined in ecRcc.h void RCC_GPIOA_enable(void); void RCC_GPIOC_enable(void); int main(void) { /* Part 1. RCC GPIOA Register Setting */ RCC_GPIOA_enable(); RCC_GPIOC_enable(); /* Part 2. GPIO Register Setting for OUTPUT*/ // GPIO Mode Register GPIOA->MODER &= ~(3UL<<(2*LED_PIN)); // Clear '00' for Pin 5 GPIOA->MODER |= 1UL<<(2*LED_PIN); // Set '01' for Pin 5 // GPIO Output Type Register GPIOA->OTYPER &= ~(1UL<PUPDR &= ~(3UL<<(2*LED_PIN)); // 00: none // GPIO Output Speed Register GPIOA->OSPEEDR &= ~(3UL<<(2*LED_PIN)); GPIOA->OSPEEDR |= 2UL<<(2*LED_PIN); //10:Fast Speed /* Part 3. GPIO Register Setting for INPUT*/ // GPIO Mode Register GPIOC->MODER &= ~(3UL<<(2*BUTTON_PIN)); // 00: Input // GPIO Pull-Up/Pull-Down Register GPIOC->PUPDR &= ~(3UL<<(2*BUTTON_PIN)); GPIOC->PUPDR |= 2UL<<(2*BUTTON_PIN); // 10: Pull-down /* Part 4. Deal loop */ while(1){ unsigned int btVal=0; //Read bit value of Button btVal=(GPIOC->IDR) & (1UL << BUTTON_PIN); if(btVal == 0) GPIOA->ODR |= (1UL << LED_PIN); else GPIOA->ODR &= ~(1UL << LED_PIN); } } void RCC_GPIOA_enable() { // HSI is used as system clock RCC_HSI_init(); // RCC Peripheral Clock for GPIO_A Enable RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN; } void RCC_GPIOC_enable() { // HSI is used as system clock RCC_HSI_init(); // RCC Peripheral Clock for GPIO_A Enable RCC->AHB1ENR |= RCC_AHB1ENR_GPIOCEN; } void RCC_HSI_init() { // Enable High Speed Internal Clock (HSI = 16 MHz) RCC->CR |= ((uint32_t)RCC_CR_HSION); // wait until HSI is ready while ( (RCC->CR & (uint32_t) RCC_CR_HSIRDY) == 0 ) {;} // Select HSI as system clock source RCC->CFGR &= (uint32_t)(~RCC_CFGR_SW); RCC->CFGR |= (uint32_t)RCC_CFGR_SW_HSI; // Wait till HSI is used as system clock source while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != 0 ); } ``` ## Software vs Hardware Debug * There are two methods to debug your program: software debug and hardware debug. * Software Debug: you do not need to connect the MCU to PC to debug a software program. * Hardware Debug: MCU board must be connected to the computer. * For this tutorial, we will use Hardware Debugging. ![image](https://user-images.githubusercontent.com/91526930/192132991-0ab53fe9-3f23-4af1-85fb-b153fc5eb425.png) ## Debug Control ### Compile, Debug, and Run * You can program the STM32 flash by clicking the LOAD button ![](https://user-images.githubusercontent.com/91526930/192132617-1cf8ef6c-f6cb-4be8-b35c-d5748253eb19.png). * Click the debug button ![image](https://user-images.githubusercontent.com/91526930/192132643-c8628ae6-4c0c-4e95-91b2-d881bbd85f3e.png) to start the debug and click it again to exit the debug. * You can use the breakpoint button ![](https://user-images.githubusercontent.com/91526930/192132654-5319d623-ed32-461e-b39c-b45709ce2033.png) to set a break point in either disassembly or source windows. * STM32 allows up to six breakpoints during hardware debugging. When a program stops at a breakpoint, the corresponding instruction has not been executed yet. * You can choose either debugging *assembly code* or *C-code* line by choosing the disassembly or source window in focus. ![image](https://user-images.githubusercontent.com/91526930/192132687-f01c0e20-9e41-45ac-8f72-b9ddbd29dbc9.png) * Control buttons of debugging ![image](https://user-images.githubusercontent.com/91526930/192132759-5ce23e5a-e89f-4864-ab21-64095b4608e0.png) * **Run (F5)**: Continues the execution from the current position until you click ***Stop*** or the program is paused by a breakpoint. * **Step In (F11)**: Execute one step and enter the function if the current step calls a function. * **Step Out (Ctrl + F11)**: Execute until the current function returns. * **Step Over (F10)**: Execute one step and run the function all at once if the current step calls a function. ### Pheripheral Registers * Choose the menu: **Peripherals** **⟶** **System Viewer** * View and update the control and data registers of all available peripherals * Check Registers for GPIO Port A (PA5 for LED). * Check the value of Output Data Register (ODR) ODR5 and LED status * Check and uncheck ODR5 with mouse click and see how LED turns on/off ![image](https://user-images.githubusercontent.com/91526930/192132973-52e62109-baf9-41e5-9bbb-ab235524a219.png) * Check Registers for GPIO Port C (PC\_13 for Button B1). * Check the value of Input Data Register (IDR) IDR13 * Keep pressing ‘F10’ while B1 button is pressing and unpressing. Check the value of IDR13. * Now, check other peripheral registers such as RCC. ### Processor Registers #### Core Registers * Program counter (PC) r15 holds the memory address (location in memory) of the next instruction to be fetched from the instruction memory. * Stack point (SP) r13 holds a memory address that points to the top of the stack. SP is a shadow of either MSP or PSP. * xPSR (Special-purpose program status registers) is a combination of the following three processor status registers: * Application PSR * Interrupt PSR * Execution PSR | xPSR | Description | | ---- | ----------------------------------------------------- | | N | Negative or less than flag (1 = result negative) | | Z | Zero flag (1 = result 0) | | C | Carry or borrow flag (1 = Carry true or borrow false) | | V | Overflow flag (1 = overflow) | | Q | Q Sticky saturation flag | | T | Thumb state bit | | IT | If-Then bits | | ISR | ISR Number (6 bits) | ![image](https://user-images.githubusercontent.com/91526930/192133259-eb544af9-3901-490c-bb51-7137134d97d7.png) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. 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