{"id":2374,"date":"2016-11-23T17:05:29","date_gmt":"2016-11-24T01:05:29","guid":{"rendered":"http:\/\/visualgdb.com\/w\/?p=2374"},"modified":"2016-11-23T17:05:29","modified_gmt":"2016-11-24T01:05:29","slug":"debugging-stm32l0-firmware-with-sleep-mode-with-openocd","status":"publish","type":"post","link":"https:\/\/visualgdb.com\/tutorials\/arm\/stm32\/sleep\/","title":{"rendered":"Debugging STM32L0 Firmware with Sleep Mode with OpenOCD"},"content":{"rendered":"

This tutorial shows how to configure VisualGDB and OpenOCD to debug STM32L0 firmware that puts the microcontroller in the sleep mode.<\/p>\n

We will create a basic project for the NUCLEO-L031K6\u00a0 board, show why the default configuration does not work when the CPU enters the sleep mode and how to work around it by using a special reset mode in debug settings.<\/p>\n

    \n
  1. Start Visual Studio and open the VisualGDB Embedded Project Wizard:\"01-prjname\"<\/a><\/li>\n
  2. Select “Create a new project -> Embedded binary” and click “next”:\"02-prjtype\"<\/a><\/li>\n
  3. Select the ARM toolchain and your device from the list. The NUCLEO-L031K6 board shown in this tutorial has the STM32L031K6 microcontroller:\"03-device\"<\/a><\/li>\n
  4. Proceed with the default “LEDBlink” sample:\"04-sample\"<\/a><\/li>\n
  5. On the last page select “OpenOCD”, connect your board via USB and click “Detect” to automatically detect debugging settings:\"05-debug\"<\/a><\/li>\n
  6. Press “Finish” to generate your project. Replace the contents of the main() function with the following:\n
    int main(void)\r\n{\r\n\u00a0\u00a0 \u00a0HAL_Init();\r\n\u00a0\u00a0 \u00a0\r\n\u00a0\u00a0\u00a0 __GPIOB_CLK_ENABLE();\r\n\u00a0\u00a0\u00a0 GPIO_InitTypeDef GPIO_InitStructure;\r\n\r\n\u00a0\u00a0\u00a0 GPIO_InitStructure.Pin = GPIO_PIN_3;\r\n\r\n\u00a0\u00a0\u00a0 GPIO_InitStructure.Mode = GPIO_MODE_OUTPUT_PP;\r\n\u00a0\u00a0\u00a0 GPIO_InitStructure.Speed = GPIO_SPEED_HIGH;\r\n\u00a0\u00a0\u00a0 GPIO_InitStructure.Pull = GPIO_NOPULL;\r\n\u00a0\u00a0\u00a0 HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);\r\n\u00a0\u00a0 \u00a0\r\n\u00a0\u00a0\u00a0 for (;;)\r\n\u00a0\u00a0\u00a0 {\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 HAL_PWR_EnterSLEEPMode(PWR_LOWPOWERREGULATOR_ON, PWR_SLEEPENTRY_WFI);\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_3);\r\n\u00a0\u00a0\u00a0 }\r\n\u00a0\u00a0 \u00a0\r\n}<\/pre>\n
    This will put the device in the sleep mode until a SysTick interrupt occurs.\"06-build\"<\/a><\/li>\n
  7. Press F5 to start debugging. The debugging should start normally and you should be able to step through the code:\"07-debug\"<\/a><\/li>\n
  8. Press Shift-F5 to stop debugging and try starting it again. Debugging will now fail with the following error shown by OpenOCD:\n
    Error: timed out while waiting for target halted<\/pre>\n
    \"08-problem\"<\/a>The error happens because while the device is in the sleep mode, OpenOCD cannot properly connect to it over JTAG.<\/li>\n
  9. Now we will show how to fix this by editing the OpenOCD configuration. Open the Debug Settings page of VisualGDB Project Properties and switch to the Manual setup<\/strong> mode:\"09-debugsetting\"<\/a><\/li>\n
  10. Click the “Open” button in the “Target” field, make a copy of the original file (e.g. to stm32l0_reset.cfg) and open it in an editor:\"11-reset\"<\/a><\/li>\n
  11. Locate the line starting with reset_config and replace it with the following one:\n
    reset_config trst_and_srst srst_nogate connect_assert_srst<\/pre>\n
    \"12-reset\"<\/a>The connect_assert_rst<\/strong> flag will force OpenOCD to reset the CPU during the initial connection, forcing it out of the sleep mode and ensuring that the debug communication succeeds.<\/li>\n
  12. Save the new script and ensure that it is selected in the VisualGDB Project Properties:\"13-newcfg\"<\/a><\/li>\n
  13. Press F5 to start debugging. The debugging should now work normally despite the firmware entering the sleep mode:\"14-debug\"<\/a><\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"
    This tutorial shows how to configure VisualGDB and OpenOCD to debug STM32L0 firmware that puts the microcontroller in the sleep<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[89],"tags":[61],"_links":{"self":[{"href":"https:\/\/visualgdb.com\/w\/wp-json\/wp\/v2\/posts\/2374"}],"collection":[{"href":"https:\/\/visualgdb.com\/w\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/visualgdb.com\/w\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/visualgdb.com\/w\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/visualgdb.com\/w\/wp-json\/wp\/v2\/comments?post=2374"}],"version-history":[{"count":1,"href":"https:\/\/visualgdb.com\/w\/wp-json\/wp\/v2\/posts\/2374\/revisions"}],"predecessor-version":[{"id":2388,"href":"https:\/\/visualgdb.com\/w\/wp-json\/wp\/v2\/posts\/2374\/revisions\/2388"}],"wp:attachment":[{"href":"https:\/\/visualgdb.com\/w\/wp-json\/wp\/v2\/media?parent=2374"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/visualgdb.com\/w\/wp-json\/wp\/v2\/categories?post=2374"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/visualgdb.com\/w\/wp-json\/wp\/v2\/tags?post=2374"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}