Zynq 7010s are $2.50 and are a hell of a lot more chip than an RP2040. If you already have the design (or copy one of the 50 available), it's a good option when you don't want to fight the chip.
PIO has extraordinarily sloppy timing (skew in all categories) compared to the cheapest and smallest FPGAs.
Where are you getting them for $2.50?? The XC7Z010-1CLG225C is $74.83 at Digikey in qty 1.
Checking sketchier places Win-Source has the CLG400 package for $22.20 and even the cheapest aliexpress seller wants $4.84 for something marked as a 7Z010 that may or may not be legit.
Also "fight the chip" is pretty much the definition of what I did last time I did a zynq project. Just give me a plain FPGA and MCU with no wizards or GUIs or automatic code generation.
I've ordered trays (and they send the OEM tray) - unique barcodes, legit.
> Just give me a plain FPGA and MCU with no wizards or GUIs or automatic code generation.
You can pretty much cut out all of their tools and get a pure Yocto/Vivado TCL build for the bitstream for the 7 series Zynqs. Very low touch.
Their IO planner (in the Vivado IP integrator) is somewhat necessary for complex peripheral scenarios and is one of the few things I ever use Xilinx GUI applications for anymore.
I was interested to see, or at least what state they're in so I grabbed a couple. Might try to compare them against some genuine ones with CT and destructive inspection.
On the chance they're half reasonable, thanks for the link.
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...
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.)
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 don’t even find Vivado that bad, but maybe I have Stockholm syndrome. Or maybe it’s because I’m forced to use Intel Quartus right now and wish it was Vivado every time.
What parts do you have to fight? I’ve been using Zynqs for about almost a decade or so, and I really enjoy them. But that’s for personal projects with a lot of freedom, so I’m curious what problems arise in more commercial/professional settings.
Nowadays, I only often wish I had their ARMv8 chips instead of the old ARMv7 32bit architecture because that’s just showing its age, but that’s par for the course of using ARMv7, and doesn’t affect the PL side (much, except for interfacing sometimes).
I've always wanted to do an FPGA project but haven't looked seriously into where to start. Can the Zynq 7010 handle something like data transfer from a 4K image sensor to a USB 3 transceiver?
> PIO has extraordinarily sloppy timing
Do you have any data on this? I was under the impression the PIO has fairly precise timing if you set up your clocks right, but maybe I've been misled here.
> Can the Zynq 7010 handle something like data transfer from a 4K image sensor to a USB 3 transceiver?
The Zynq 7010 is less-than-ideal for this because you'd have to use some kind of USB3 interface PHY - which would increase cost and be pretty limited functionality-wise.
The Z7010 probably has the area to do this type of translation but not the transceivers. There are other chips in the 7 series Zynq family with capable transceivers, but they are much more expensive ($15-$35 from CN).
> I was under the impression the PIO has fairly precise timing if you set up your clocks right, but maybe I've been misled here.
No measured data, but when I was once implementing JTAG and SPI at 50MHz+ with an extremely overclocked chip, the edges were very inconsistent in relation to each other and in pulse width - 5-15ns (estimating from memory, they were sloppy.)
PIO is very precise within its specified capabilities, this range is just very low compared to cheap FPGAs.
Thanks for the reply and the links! I'm okay with a more expensive FPGA chip if it significantly simplifies the implementation. I'm probably biting off more than I can chew trying to start FPGA dev with something like this, so I'll also look into simpler starter projects.
> PIO is very precise within its specified capabilities, this range is just very low compared to cheap FPGAs.
Good to know, I don't plan on pushing RP2040s to their limit any time soon. They're still excellent for lower speed projects.
PIO has extraordinarily sloppy timing (skew in all categories) compared to the cheapest and smallest FPGAs.