GigaDevice GD32

The GD32 Cortex-M Series is family of devices by GigaDevice Semiconductor Inc.
The following article contains information which applies to all members of the product family (e.g. readout protection).
Information which is more specific to the respective sub-family(e.g. QSPI programming) is provided in family specific articles.

A list of all GigaDevice devices supported by SEGGER can be found here.
For further information regarding the product family, please refer to the website and documentation by GigaDevice.

Device specific connect

To provide the best debugging experience for the most common setups, a device specific connect is implemented for the STM32 devices.

Note:
If for some reason this device specific connect causes issues for a certain setup, users can override the device specific connect.

Debug registers

The STM32 devices come with multiple debug registers (DBG / DBGMCU). Some of these registers are written by J-Link during connect, to provide a good debugging experiance:

• Enabling watchdog timer freeze on debug halt.
• Enabling debugging during Sleep, Standby & Stop modes.

Note:

• The used registers will be reset to their reset value on disconnect.
• The J-Link expects that these registers are written by J-Link only and not by the target application!

Device security

On connect, the device security is checked. If security is set (and recoverable) the user is asked if they want security to be lifted. If the user agrees, security is lifted by J-Link (if possible).

Note:

• It is possible to disable debugging completely, by setting ROP/RDP Level == 2. A connect will not be possible anymore afterwards and the security cannot be reset.
• The device is briefly halted while checking security. This is done because in some cases, device security might be detected wrongly while the device is running.
• In most cases, unsecuring the device causes a mass erase of the flash.
• It is possible to save the selection of the unlock dialog. To reset this, please refer to: Reset unlock message box.

Connect under reset

In case that J-Link fails to connect to the device (usually caused by a low-power state of the MCU), J-Link will try to connect to the device under reset to make debugging possible.