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Anyhow, I recently made a wirespeed Ethernet packet sniffer on my development board, all pure logic - no CPU, big fun. I want to extend on that.

That's very impressive. It must have been a steep learning curve if you came straight from software into an FPGA. Gigabit Ethernet is going to be a tough one for a first board but given what you've achieved already I'm sure you're up to figuring out the hard parts. Board layout will be crucial at the speeds involved here. If the manufacturer has a development board where you can see the PCB layout then use it as a reference.

- Since I'm not using the internal LDO, can I drop connecting it?

The datasheet says that you can leave it floating in the pinout table. Question is, why not use it? An LDO is going to be quieter than a switcher and the LDO onboard is going to be matched to the requirements of the chip.

- Do I still need capacitors close to the power pins on the PHY chip? (As in Figure 7 from the app notes)

Yes, and they'll need to be good quality which means X5R/X7R for the larger ceramics and C0G/NP0 for the smaller ones.

- What is the recommended way to wire up the DVDDH 3.3V?

It looks like it sets the level for the digital IO interface. So supply it with 3.3/2.5/1.8V to match the IO levels coming from the FPGA board.

I don't use solder paste. I tried some of that 'mechanic' stuff you get on ebay without the benefit of a stencil and it sort of worked but was really messy. Without a stencil you will get it on the soldermask where it will form little annoying solder balls when reflowed that all have to be cleared off. Some years later I decided to try again with some quality (£20 a syringe) stuff from Farnell and even got a laser cut stencil. It was still messy and with all the faffing around with alignment it would have been just as quick and much less messy to just tin the pads with an iron, which it is what I've always done and continue to do today.

Then there's the expense. Good paste is orders of magnitude more expensive than solder wire, has a limited shelf life and needs refrigerating which I cannot do in a household fridge used for food! It might just be me, after all it's because of the posts and how-to guides on the internet that I tried (twice) at all but I'm leaving paste to the pick-and-place assembly line and sticking to my ancient soldering iron!

PS. You can add liquid flux to solidified paste to bring it back to life, though maybe not with the same properties as it had when it was new.

I noticed the bios will not report any temperature and thus the fans run at highest speed. Don't need to say it is super loud!!!

Do you mean the CPU fans? With mine they run at minimum speed all the time so I run SpeedFan to dynamically control the speed based on temperature. You've probably seen my post on how to do this, but here's the link anyway.

I've released version 4.0.5. It contains some useful optimisations for size and speed. You can read the detail on github.

Quite some time ago I bought a GPS Disciplined Oscillator (GPSDO) on ebay to calibrate my Nanocounter frequency counter project.



I've now got around to reviewing it and taking it apart to see what's inside. Click here to read the article.

Hi Randy,

Creating an 072-specific build should be quite straightforward because it is supported by the standard peripheral library and is quite similar to the other supported F0 builds. I actually considered doing an F072 build for the nanocounter project but in the end didn't bother because the F051 build was close enough to work.

To get started, search the source code for all occurrences of something like 'STM32PLUS_F0_51'. You'll be creating a similar macro 'STM32PLUS_F0_72' and using it wherever it's appropriate.

Windows 10 Pro is the OS that I used to create these instructions and I haven't installed any unusual drivers. Speedfan just worked out of the box. Do you see the "ADT7490" being detected in the "Readings" information box?

Hi Carlos,

The build scripts have to work on all platforms: Linux, Windows and Mac and they can't make assumptions about where someone has installed the toolchain on their local system. For that reason you're expected to have your PATH variable set so that it picks up the toolchain that's correct for your local installation.

Fundamentally the issue is that stm32plus depends throughout on the standard peripheral library which has now been replaced for the new MCU lines with the HAL. If the L0 is similar enough to the F0 then you might find that peripherals common to both will 'just work' because the register locations and formats are the same so standard peripheral library methods designed for the F0 will work on the L0. This is just my guesswork though. Try compiling the 'blink' example targeting the F030 and upload it to the L031 (with startup files modified for the L0).

If you need support for peripherals unique to the L0 then you'd have to use the HAL (or registers) to access them and your approach of creating a new section in config/stdperiph.h is the right way. Personally I think that the HAL is so badly written I'd be sorely tempted to just go straight for the registers if the peripheral is simple enough.

If you've already modded the motherboard tray with holes to accept the screws from the odd positions on the Z800 motherboard then the hard bit's out of the way in my opinion. By the way I forgot to mention that with all memory slots full you will need a fan directing airflow through the memory slots. When there are so many so close together they tend to heat each other up.

I am using Rev A01, Silver Heatsink ATM. With 16k R11 : 3.4k R10 divider it happily goes down to 500mv, but I don't think the soft-start likes it until up and around 1v (with a load on it at least) - that is with the std RT frequency. So VSEN manipulation gets you 0.5-6.5V out of the box.

Does PGOOD stay high at all those voltages?

You did very well to get a 900D for just $50. That's one heck of a case. It would be nice to see photographs of it with the Z800 board inside.

144GB DDR3 10600R

We now know that it's an NXA66 and enough of a datasheet is available for download to work with it. It's capable of two fixed output voltages. 3.3V and whatever you get after grounding VSP. I now have two modules, the one you see in the blog post from a Dell server will output 5V with VSP grounded which is contrary to the datasheet's claim of 2.5V so I bought a second module that looks the same except it has a silver coloured heatsink and is labelled Rev A01. This new one outputs 2.5V with VSP grounded as the datasheet claims. So there are two variants out there, both with very useful output levels and spec'd for up to 20A continuous output current.

There's also a differential SENSE input that, although not properly documented in the datasheet, is highly likely to be used to compensate for voltage drop at the load. I intend to experiment with these to see what happens.

I'm currently designing a PCB to mount this board on with some typical PSU features. I hope to make it simple to construct (through hole) so anyone can pick one of these up from the 'bay and build a nice little PSU around a very solid module.

SpeedFan works for me on W10Pro, but it ranks the fan up to 100%(5000rpm) as soon as temps raise even by a bit, doesn't matter how i adjust the temperature curve.

That doesn't sound right at all. Can you double-check on the page with the speed chart on it that both CPU0 and CPU1 are set to "MAX of speeds" and not "SUM of speeds".

Back on the main speedfan page you should be able to watch the two circled speeds changing in response to the temperature.

My Zalman CPU fans have reached the end of their useful life and I've replaced them with some shiny new ones. I've updated the main article with all the details including audio recordings of the failing fans and some pictures of the new ones.