ST-LINK/V3 ?

[photovore]

When updating my IAR compiler service pack I saw that ST-LINK V3 support was one of the new features. Is there any info concerning this new version of the debugger? I quite enjoy the integrated UART in the ST Dev Boards and was wondering when they would add the feature to their official hardware.  Higher SWD speeds also wouldn't hurt.

[ajb]

Looks like it's already for sale: https://www.aliexpress.com/item/New-STLINK3-st-link3-st-link-V3-STM32-STM8-emulator/32815460150.html

[andersm]

The STM32CubeProgrammer manual gives 24000kHz SWD and 21333kHz JTAG frequencies for the ST-Link v3 (via).

[technix]

The STM32CubeProgrammer manual gives 24000kHz SWD and 21333kHz JTAG frequencies for the ST-Link v3 (via).

That usually means 96MHz or higher core clock. What for?

[lucazader]

It appears this is now in stock at both digikey and mouser:
https://www.digikey.com/product-detail/en/stmicroelectronics/STLINK-V3SET/497-18216-ND/9636028
https://nz.mouser.com/ProductDetail/511-STLINK-V3SET

Here is a recently added technical doc that was added to ST's website explaining the differences in the different ST-link versions, it includes info about the ST-Link V3:
https://bit.ly/2QuEBOd

Headline features:
Based on STM32F723IE processor
USB 2.0 HS interface (rather than FS on all older stlinks)
Integrated VCP port with frequency up to 15MHz (assuming this means up to 15mhz uart)
USB Bridge interface with support for: SPI/UART/I2C/Can?GPIO

In addition to this the STCubeProgrammer has been updated to V1.2 which apparently now fully supports the V3 hardware.
Assuming the 24MHz SWD frequency still stands, but cant find any more info on this.

[richardman]

That "USB 2.0 HS interface (rather than FS on all older stlinks)" could be very useful.

Currently STLINK is very slow, especially with the ST-LINK GDBserver, but apparently that's just because they have not upgraded the programming algorithm yet, but a faster interface should help.

[ajb]

USB HS is hardly likely to make any difference at all in many cases.  Programming time is dominated by the erase/write timing of the flash; the time it takes to move the data from the PC to the debug probe is nothing by comparison.  Anyway, ST parts max out at, what, 2MB of flash?  It's possible that the new probe will be accompanied by better algorithms and better software support, though, which would be quite welcome.  I especially hope it now properly supports connecting to a running target, and doesn't need to be power cycled if it falls to connect to the target, like the V2.  Personally I'll probably stick with the J-link, which is waaaaay faster and more reliable than the V2.

[ajb]

More info available now, including what the hardware looks like.  The adapter board is as big as the probe is!  Looks like it can be stacked into the same housing as the probe which is sort of neat, but I would rather have a slightly larger device than one that has pins and cables coming off of every side.

https://www.st.com/content/st_com/en/products/development-tools/hardware-development-tools/development-tool-hardware-for-mcus/debug-hardware-for-mcus/debug-hardware-for-stm32-mcus/stlink-v3set.html#design-scroll

[SiliconWizard]

It's only 3 V to 3.6 V apparently which sucks. There seems to be an adapter board for 1.65 V to 5.5 V but I'm not sure what SWIM is exactly.

[andersm]

I'm not sure what SWIM is exactly.

It's the debug protocol for ST8 micros.

[SiliconWizard]

Thanks, so I take it that for STM32's you are stuck with 3V min (unless you add your own level shifters)?

[trevwhite]

I was going to buy one of these but seems they are now unavailable? Production issue? Design issue? Anyone have any idea what happened to supply?

Trev

[SiliconWizard]

Indeed: https://www.st.com/en/development-tools/stlink-v3set.html

Guess you'll have to contact them as they suggest.

[Mr. Scram]

It's only 3 V to 3.6 V apparently which sucks. There seems to be an adapter board for 1.65 V to 5.5 V but I'm not sure what SWIM is exactly.

What would be the practical implications of the voltage limitation? I was thinking of buying a V3, but maybe a V2 is more versatile.

[SiliconWizard]

It's only 3 V to 3.6 V apparently which sucks. There seems to be an adapter board for 1.65 V to 5.5 V but I'm not sure what SWIM is exactly.

What would be the practical implications of the voltage limitation? I was thinking of buying a V3, but maybe a V2 is more versatile.

Well, I guess you wouldn't be able to use it on a board powering the MCU at any voltage under 3V. You may not design any and in this case, no bother. I happen to use Vdd's anywhere from 1.8V to 2.7V in some of my designs, so that would be a problem.

The V2 was a lot more flexible: "1.65 V to 3.6 V application voltage supported on the JTAG/SWD interface and 5 V tolerant inputs".

[lucazader]

You would have to assume that this new board would be compatible with lower voltage targets on the SWD pins, given they just announced the STM32L5 series that is specifically targeted at this sort of low power low voltage type of application.
I have ordered one from digikey, but not sure when it will arrive...
I can try and test it out at a lower voltage when mine gets to me? However all my designs are 3v3, so might have to modify a nucleo board or something to test this..?

[technix]

I think ST may have a Vpp problem when writing Flash below 3.3V, so it just doesn’t make sense to support anything lower just not to trigger those bugs.

[Mr. Scram]

I think ST may have a Vpp problem when writing Flash below 3.3V, so it just doesn’t make sense to support anything lower just not to trigger those bugs.

That sounds like a great way of getting people to look at other manufacturers.

[SiliconWizard]

I think ST may have a Vpp problem when writing Flash below 3.3V, so it just doesn’t make sense to support anything lower just not to trigger those bugs.

I've only used the L4 series so far, but never ran into such issues with them. Could you point us to some official erratum that clearly states this and what series/models are affected?

If this happens to be true for some models or worse, maybe for ALL of them as you seem to suggest, that would not bode well for ST at all. How would you be supposed to power your MCU at voltages below 3.3V and still be able to program them in-circuit (or have them self-program)? (Except having to design pretty convoluted circuits that can switch to 3.3V just for programming?!)

[technix]

I've only used the L4 series so far, but never ran into such issues with them. Could you point us to some official erratum that clearly states this and what series/models are affected?

If this happens to be true for some models or worse, maybe for ALL of them as you seem to suggest, that would not bode well for ST at all. How would you be supposed to power your MCU at voltages below 3.3V and still be able to program them in-circuit (or have them self-program)? (Except having to design pretty convoluted circuits that can switch to 3.3V just for programming?!)

You just need a diode between the STM32 Vcc and main power rail. This way when programming the programmer/debugger can inject a 3.3V into the STM32 power domain without affecting the rest of the system. As of self program, you are not supposed to do that without a high enough Vcc in the first place. My usual F0 and F4 series can have flaky programming behavior at 2.5V or lower.

That sounds like a great way of getting people to look at other manufacturers.

You are not supposed to program at lower voltages in the first places as documented, and for most uses I know of the STM32 does operate with a 3.3V rail. I feel that ST is just not bothering with the maybe 5% case anymore.

[SiliconWizard]

You just need a diode between the STM32 Vcc and main power rail. This way when programming the programmer/debugger can inject a 3.3V into the STM32 power domain without affecting the rest of the system.

I don't like that. I don't like a voltage drop between the MCU's VDD and the rest of the system in normal condition.

You are not supposed to program at lower voltages in the first places as documented, and for most uses I know of the STM32 does operate with a 3.3V rail. I feel that ST is just not bothering with the maybe 5% case anymore.

I think you're stuck to the F-series/"high-performance" STM32's. Operating voltages below 3.3V are very common in low-power, battery-operated designs. And the STM32L series are targetted at this market, and very well positioned actually. I have read nothing about a higher min programming voltage than the min operating voltage (1.71V as I reckon) in the L4 series datasheets.

I'm looking for this info in a STM32F407 datasheet right now and now get why you said that. Seems specific to the F4 (and maybe other F-series). There's a stated Vprog which depends on the program width actually. 32-bit programming requires 2.7V min, but 8-bit programming can be done at 1.8V, so there's still a way to program them reliably down to 1.8V provided that you can force the 8-bit programming mode. There's no such restriction that I know of for the L-series, they don't even mention specific Vprog figures.

I'm guessing this limitation on the STLINK/V3 vs. V2 comes more from a cost reduction strategy than anything else. Since it's a stated "modular" design, they may release a wider operating voltage through some adapter for JTAG/SWD later on.

As for me, I'll definitely stick to a JTAG-lock-pick Tiny 2 which is much faster than the STLINK (at least up to V2), works down to 1.4V and can be used with many other chips.

[Jeroen3]

It looks like it will support the 1.27mm connector. No need to use adapters boards!

[technix]

You just need a diode between the STM32 Vcc and main power rail. This way when programming the programmer/debugger can inject a 3.3V into the STM32 power domain without affecting the rest of the system.

I don't like that. I don't like a voltage drop between the MCU's VDD and the rest of the system in normal condition.

There are some low leakage perfect diode circuitry available.

You are not supposed to program at lower voltages in the first places as documented, and for most uses I know of the STM32 does operate with a 3.3V rail. I feel that ST is just not bothering with the maybe 5% case anymore.

I think you're stuck to the F-series/"high-performance" STM32's. Operating voltages below 3.3V are very common in low-power, battery-operated designs. And the STM32L series are targetted at this market, and very well positioned actually. I have read nothing about a higher min programming voltage than the min operating voltage (1.71V as I reckon) in the L4 series datasheets.

I'm looking for this info in a STM32F407 datasheet right now and now get why you said that. Seems specific to the F4 (and maybe other F-series). There's a stated Vprog which depends on the program width actually. 32-bit programming requires 2.7V min, but 8-bit programming can be done at 1.8V, so there's still a way to program them reliably down to 1.8V provided that you can force the 8-bit programming mode. There's no such restriction that I know of for the L-series, they don't even mention specific Vprog figures.

I'm guessing this limitation on the STLINK/V3 vs. V2 comes more from a cost reduction strategy than anything else. Since it's a stated "modular" design, they may release a wider operating voltage through some adapter for JTAG/SWD later on.

As for me, I'll definitely stick to a JTAG-lock-pick Tiny 2 which is much faster than the STLINK (at least up to V2), works down to 1.4V and can be used with many other chips.

I do use mostly the F-series. If the Vpp problem originated from me getting questionable Chinese chips things are explained.

Now it feels odd to me that they did not implement proper bidirectional level shifting. AFAIK the whole level shifting thing can be easily handled using a few 74LVC1T45/2T245’s, and their previous hardware do have those.

[SiliconWizard]

Now it feels odd to me that they did not implement proper bidirectional level shifting. AFAIK the whole level shifting thing can be easily handled using a few 74LVC1T45/2T245’s, and their previous hardware do have those.

As said above, I'm pretty sure this is for cost reduction reasons. The V3 design looks like a low-cost version of the V2 in almost all aspects. The HS USB probably costs only a few cents more if even so and doesn't make up for the fact everything else is worse: the V2 had an isolated version, I haven't seen that for the V3. The V2 case was a lot better. And so on...

And I really suggest using other tools than the STLINK if you can. But this V3 looks like a great disappointment so far.

[technix]

Now it feels odd to me that they did not implement proper bidirectional level shifting. AFAIK the whole level shifting thing can be easily handled using a few 74LVC1T45/2T245’s, and their previous hardware do have those.

As said above, I'm pretty sure this is for cost reduction reasons. The V3 design looks like a low-cost version of the V2 in almost all aspects. The HS USB probably costs only a few cents more if even so and doesn't make up for the fact everything else is worse: the V2 had an isolated version, I haven't seen that for the V3. The V2 case was a lot better. And so on...

And I really suggest using other tools than the STLINK if you can. But this V3 looks like a great disappointment so far.

v3 bumped the processor to a F7 from a F103, a fairly significant jump, so unlikely to be a cost reduction revision.