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Memory Mapping an FPGA from an STM32

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Re: Memory Mapping an FPGA from an STM32

#61

Post by scottapotamas »

15155 wrote: post #58
scottapotamas wrote: post #57

Earlier quoted context omitted.

Will do. Not too worried about trying low cost parts to gain some minimal confidence in a possible source, they're compelling for weekend side-projects at least. I've previously struggled to roll the dice for higher end parts as the cost difference isn't as extreme and had some obvious reballed parts a few years ago. If they're OK then their $20 XC7K325T will be at the top of my list...

At $20, just buy from LCSC- https://www.lcsc.com/product-detail/Programmable-Logic-Devic... https://www.lcsc.com/product-detail/Microcontroller-Units-MC...

That's low-end Zynq and Artix and I'm thinking more >676 Kintex, though I appreciate any discussion on sourcing.

In the way that that Aliexpress vendor lists the 7010 parts at 1/10th the price of LCSC, some of their $20-60 listings are also shockingly cheap in comparison.

Re: Memory Mapping an FPGA from an STM32

#62

Post by 15155 »

scottapotamas wrote: post #61
15155 wrote: post #58

Earlier quoted context omitted.

At $20, just buy from LCSC- https://www.lcsc.com/product-detail/Programmable-Logic-Devic... https://www.lcsc.com/product-detail/Microcontroller-Units-MC...

That's low-end Zynq and Artix and I'm thinking more >676 Kintex, though I appreciate any discussion on sourcing. In the way that that Aliexpress vendor lists the 7010 parts at 1/10th the price of LCSC, some of their $20-60 listings are also shockingly cheap in comparison.

Ah, missed the K! For the K420T, I pay around $30-45 from CN (not Aliexpress) sources with original barcodes (but these vendors are quite a bit harder to deal with.)

Re: Memory Mapping an FPGA from an STM32

#63

Post by azonenberg »

scottapotamas wrote: post #57
15155 wrote: post #50

Earlier quoted context omitted.

Let me know if the barcodes are anything but unique/perfect. This has been the case with many vendors, but these chips are cheap enough that you can try 50 vendors.

Will do. Not too worried about trying low cost parts to gain some minimal confidence in a possible source, they're compelling for weekend side-projects at least. I've previously struggled to roll the dice for higher end parts as the cost difference isn't as extreme and had some obvious reballed parts a few years ago. If they're OK then their $20 XC7K325T will be at the top of my list...

I have some obviously reballed (but well done) aliexpress XCKU5P's that I got for $55 a while back. Haven't tested yet but the price was so good I couldn't resist.

Re: Memory Mapping an FPGA from an STM32

#64

Post by mindentropy »

mystified5016 wrote: post #25
dmitrygr wrote: post #19

Be veeeery careful. STM32H QSPI peripheral is FULL OF very nasty bugs, especially the second version (supports writes) that you find in STM32H0B chips . You are currently avoiding them by having QSPI mapped as device memory, but the minute you attempt to use it with cache or run code from it, or (god help you) put your stack, heap, and/or vector table on a QSPI device, you are in for a world of poorly-debuggable 1:1,…

What the hell is going on at ST? Every STM uC I've tried to use in the past few years has had showstopper bugs with loads of very similar complaints online dating back to the release of the part. Bugs that have been in the wild for years and still exist in the current production run. After burning enough company time chasing bugs through ST's crappy silicon, I've had to just swear them off entirely. We're an Atmel ho…

Have you tried PSoC parts? How does that stack with other microcontrollers?

Re: Memory Mapping an FPGA from an STM32

#65

Post by scottapotamas »

azonenberg wrote: post #63
scottapotamas wrote: post #57

Earlier quoted context omitted.

Will do. Not too worried about trying low cost parts to gain some minimal confidence in a possible source, they're compelling for weekend side-projects at least. I've previously struggled to roll the dice for higher end parts as the cost difference isn't as extreme and had some obvious reballed parts a few years ago. If they're OK then their $20 XC7K325T will be at the top of my list...

I have some obviously reballed (but well done) aliexpress XCKU5P's that I got for $55 a while back. Haven't tested yet but the price was so good I couldn't resist.

I’ve been bitten before but the risk/reward is probably worth it for parts like that.

Thanks for your write-ups btw, been following glScope development for a while.

Re: Memory Mapping an FPGA from an STM32

#66

Post by anitil »

kevin_thibedeau wrote: post #46
anitil wrote: post #45

Earlier quoted context omitted.

It seems endemic with embedded devices. Only big customers get the true list of errata, and of course the errata are random PDFs rather than a useful format. Even just having them on an ftp site with all the errata in one spot would save so much pain!

Sometimes you don't even get a PDF. Their Ethernet drivers for Cortex-M7 have been broken for years with subtle cache coherency bugs and the only discussion of it is a forum thread with now obsolete example code.

Oh no! I luckily never dealt with the ethernet drivers, but I had plenty of small issues with other drivers
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