GigaDevice GD32

The GD32 contains several families 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.

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.

MCU Security

GD32 devices can have up to 3 different protection level:

Level	Description	OB_SPC value
None	Full access to flash, OTP, data flash, EEPROM and option byte from the debugger.	0xA5
Low	No access to flash, OTP, data flash and EEPROM from the debugger. Only option byte is accessible.	Any value except 0xA5 or 0xCC
High	No access to flash, OTP, data flash, EEPROM and option byte from the debugger. This state is not recoverable. This Level is not present on all devices.	0xCC

OB_SPC_N has to be set to the complement value of OB_SPC.

Disabling readout protection

J-Link Commander and J-Flash

J-Link Commander and J-Flash automatically detects secured GD32 devices and ask the user if it should be unlocked on connect.
This is called native unlock.

Note:

• It is possible to disable device access completely, by setting protection level to high. A connect will not be possible anymore afterwards and the security cannot be reset.
• 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.

Flasher standalone mode

In order to unlock a GD32 device in stand-alone mode, the unlock sequence is executed automatically if a secured device is detected.

Enabling readout protection

J-Link Commander

The below provided J-Link Commander command files set the protection level low (OB_SPC = 0x11 / OB_SPC_N = 0xEE).
On certain devices this is called "Under protection" in the reference manual.

J-Flash and Flasher standalone mode

Please use the *.hex files below for J-Flash and append to your application hex file. Take care of the adjustment of the other settings in option byte 0 area for your hardware.

How to set protection level high

In order to set protection level high, the value "0x11" needs to be changed to "0xCC" and "0xEE" to "0x33".
Please note that protection level high is permanent and can neither be reverted by SEGGER nor by GigaDevice.

Device Table

GD32 series overview

Sub-Family	Core	Protection Levels	J-Link Commander and J-Flash: native Unlock support	J-Link Commander: Lock via command file	J-Flash: Lock via hex file (adjust to your setup)	J-Flash: Lock via exit steps
GigaDevice_GD32A5	Cortex-M33	None/Low/High		GD32A5_Lock.jlink	GD32A5_Lock.mot	n/a
GigaDevice_GD32C1	Cortex-M4	None/Low		GD32C1_Lock.jlink	GD32C1_Lock.mot	n/a
GigaDevice_GD32E1	Cortex-M4	None/Low		GD32E1_Lock.jlink	GD32E1_Lock.mot	n/a
GigaDevice_GD32E2	Cortex-M4	None/Low/High		GD32E2_Lock.jlink	GD32E2_Lock.mot	n/a
GigaDevice_GD32E5	Cortex-M33	None/Low/High		GD32E5_Lock.jlink	GD32E5_Lock.mot	n/a
GigaDevice_GD32F1	Cortex-M3	None/Low/High		GD32F1_Lock.jlink	GD32F1_Lock.mot	n/a
GigaDevice_GD32F2	Cortex-M3	None/Low		GD32F2_Lock.jlink	GD32F2_Lock.mot	n/a
GigaDevice_GD32F3	Cortex-M4	None/Low		GD32F3_Lock.jlink	GD32F3_Lock.mot
GigaDevice_GD32F4 (GD32F403)	Cortex-M4	None/Low		GD32F403_Lock.jlink	GD32F403_Lock.mot	n/a
GigaDevice_GD32F4 (GD32F4xx)	Cortex-M4	None/Low/High		GD32F4xx_Lock.jlink	n/a	n/a
GigaDevice_GD32L23	Cortex-M23	None/Low/High		GD32L23_Lock.jlink	GD32L23_Lock.mot	n/a
GigaDevice_GD32H7	Cortex-M7	None/Low/High		GD32H7_Lock.jlink	n/a	n/a
GigaDevice_GD32VF103	RISC-V	None/Low		GD32VF1_Lock.jlink	GD32VF1_Lock.mot	n/a
GigaDevice_GD32VW5	RISC-V	None/Low		GD32VW5_Lock.jlink	n/a	GD32VW5_Lock.jflash