The ST STM32U5 series are 32-bit ultra low power microcontrollers based on the ARM Cortex-M33 processor.
- 1 Device family
- 2 Flash
- 3 Reset
- 4 Debug specific
- 5 Option byte programming
- 6 Securing/unsecuring the device
- 7 TrustZone
- 8 Example Application
- 9 Tracing on ST STM32U5
The STM32U5 device family consists of several subfamilies: STM32U57xxx, STM32U58xxx, STM32U59xxx and STM32U5Axxx.
The following flash regions are supported by J-Link.
|Main flash memory|
|STM32U5xxxG||Secure||0x0C00_0000 - 0x0C0F_FFFF||1024 KB|
|Non-secure||0x0800_0000 - 0x080F_FFFF|
|STM32U5xxxI||Secure||0x0C00_0000 - 0x0C1F_FFFF||2048 KB|
|Non-secure||0x0800_0000 - 0x081F_FFFF|
|STM32U5xxxJ||Secure||0x0C00_0000 - 0x0C3F_FFFF||4096 KB|
|Non-secure||0x0800_0000 - 0x083F_FFFF|
|All||---||0x9000_0000 - 0x93FF_FFFF (max)||64 MB (max)|
- See: QSPI support
The ST STM32U5xxx device series comes with a OCTASPI controller which allows memory mapped read accesses to any (Q)SPI flash, connected to the Octa-SPI interface of the MCU. This allows the J-Link DLL to support flash programming through the Octa-SPI interface. Unfortunately, there is no generic way how to implement flash programming because the pins used to connect the SPI flash are not defined. Different pins can be used for the same OCTASPI alternate function and therefore, for each configuration, a slightly different RAMCode (different pin initialization / flash size) is required. Our flash algorithms are based on the pin configurations used on the official evaluation boards. For pin configuration, different from the one used in the example flash algorithm, please get in touch with SEGGER directly via our support system: https://www.segger.com/ticket/.
For further information regarding this as well as the flash algorithm, please refer to the following pages:
- STM32U5xx: STM32U585 Discovery
For the STM32U5 devices, the Cortex-M default reset strategy is used.
Please refer to the generic STM32 article.
Option byte programming
Direct option byte programming is not (yet) implemented for the ST STM32U5. However, the same method used to lock/unlock the devices can be used as described in Securing/unsecuring the device can be used to adjust any option bytes.
Securing/unsecuring the device
Please refer to the generic STM32 article.
Flash programming with TrustZone enabled (TZEN = 1) is supported.
RDP level 0 and 0.5 is also supported. The RAMCode is only usable with RDP level 0, for RDP level 0.5 a RAMless flashloader has to be used. This is a technical limitation. The J-Link software is not able to decide at runtime when to use the RAMCode or RAMless flashloader. If you want to use the RAMless flashloader for RDP 0.5, you have to add "_RAMLess" to the device name, e.g. use "STM32U599NJ_RAMLess" instead of "STM32U599NJ". Please note that a significantly lower programming speed has to be expected with the RAMless flashloader.
The following example project was created with the SEGGER Embedded Studio project wizard and should run out-of-the-box on any ST STM32U5xxxx device. It is a simple for loop incrementing the integer i. The application is linked into the internal flash.
- J-Link software: V6.99a
- Embedded Studio: V5.34 (or later)
- Hardware: Socket board with ST STM32U5 mounted
- Link: File:ST STM32U5xxxx TestProject ES V534.zip
Tracing on ST STM32U5
Tracing on ST STM32U575
The following project has been tested with the minimum requirements mentioned and a ST STM32U575I-EVAL evaluation board.
In order to use trace on the ST STM32U575 MCU devices, the following minimum requirements have to be met:
- J-Link software version V7.66d or later
- Ozone V3.26b or later (if streaming trace and / or the sample project from below shall be used)
- J-Trace PRO for Cortex-M HW version V1.0 or later for streaming trace
To rebuild the project our IDE Embedded Studio can be used. The recommended version to rebuild the projects is V6.30. But the examples are all prebuild and work out-of-the box with Ozone, so rebuilding is not necessary.
Example Project: ST_STM32U575I_EV_TraceSample.zip
Reference trace signal quality
The following pictures show oscilloscope measurements of trace signals output by the "Tested Hardware" using the example project. All measurements have been performed using a Agilent InfiniiVision DSO7034B 350 MHz 2GSa/s oscilloscope and 1156A 1.5 GHz Active Probes. If your trace signals look similar on your trace hardware, chances are good that tracing will work out-of-the-box using the example project. More information about correct trace timing can be found at the following website.
The rise time of a signal shows the time needed for a signal to rise from logical 0 to logical 1. For this the values at 10% and 90% of the expected voltage level get used as markers. The following picture shows such a measurement for the trace clock signal.
The setup time shows the relative setup time between a trace data signal and trace clock. The measurement markers are set at 50% of the expected voltage level respectively. The following picture shows such a measurement for the trace data signal 0 relative to the trace clock signal.