This article describes device specifics of the Infineon XMC1000 microcontroller.
Boot Mode Index (BMI)
The XMC1000 family supports different boot modes. The actual boot mode is configured in the Boot Mode Index (BMI) which is a 2 byte value stored in the flash and holding information about the boot mode (start-up mode) and the debug configuration of the device. Depending on the configured boot mode, different debug pins are used for the debug communication. For a overview of all different boot modes and the used debug pins, please refer to XMC1000#Overview_BMI_Modes
The XMC1000 series devices are shipped with boot mode ASC Bootstrap Loader mode (ASC_BSL). Unfortunately, the debug interface of the device is disabled in this mode. So when using J-Link or Flasher, the boot mode needs to be changed prior a target connection can be established.
By default, the J-Link performs the switching sequence to SWD0 (P0.14 & P015 used for SWD) if the BMI of the device is ASC_BSL. If a BMI other than SWD0 is required, the default behavior can be simply overwritten using a J-Link Script File. Please find below script files for the other boot modes:
- ASC_BSL to SWD1: Infineon_XMC1000_PCode_SWD1.pex
- ASC_BSL to SPD0: Infineon_XMC1000_PCode_SPD0.pex
- ASC_BSL to SPD1: Infineon_XMC1000_PCode_SDP1.pex
Please note that the J-Link Script Files are pre-compiled (*.pex) thus they neither contain plaintext nor can be modified. If you feel that you need a modified version of the script file, please get in contact with SEGGER directly (e.g. via E-Mail / forum). For further information how to use the J-Link Script File in your environment please refer to https://wiki.segger.com/Using_J-Link_Script_Files
- The required switching sequence needs to be performed over a half-duplex UART communication on the TMS/SWDIO pin (Pin7) thus this pin needs to be connected to be able to change the BMI
- The bootstrap loader of the XMC1000 becomes confused if invalid / incorrect data have been sampled. To prevent unexpected behavior, we recommend to perform a power-on-reset of the target before establishing a connection using J-Link
- The BMI configuration is stored in the flash and therefore survives a power-on-reset of the device
Overview BMI Modes
The table below represents the available boot mode index (BMI) configurations and the used pins in this mode.
|ASC Bootstrap Load Mode (ASC_BSL)||Factory default half-duplex UART|
|User Mode (Productive)|
|User Mode (Debug) SWD0||P0.14 & P0.15 used for SWD|
|User Mode (Debug) SWD1||P1.3 & P1.2 used for SWD|
|User Mode (Debug) SPD0||P0.14 used for SPD|
|User Mode (Debug) SPD1||P1.3 used for SPD|
|User Mode (HAR) SWD0||P0.14 & P0.15 used for SWD|
|User Mode (HAR) SWD1||P1.3 & P1.2 used for SWD|
|User Mode (HAR) SPD0||P0.14 used for SPD|
|User Mode (HAR) SPD1||P1.3 used for SPD|
For further information regarding the BMI, please refer to the technical reference manual of the Infineon XMC1000 series.