3 ms·

It's great to see that dedicated hackers can get their hands on the hardware and data-sheets needed to design and manufacture these kind of high performance pro

by JDuMond 14y ago

It's great to see that dedicated hackers can get their hands on the hardware and data-sheets needed to design and manufacture these kind of high performance projects. There still remains one huge barrier before we'll see a large number of projects like this: the costs of the equipment used to validate the signal integrity on high speed digital systems like this immense. I'm hoping that soon enough Moore's law will work it's magic in the prices of signal validation equipment and at least a few hacker spaces will be able to gather enough cash to pony up for a 10 GHz scope and a nice logic analyser.

TerraHertz 14y ago
Actually it's been easily possible for years. Just forget about buying new equipment and buy older Tektronix or HP sampling scopes on ebay. For eg the HP 54121T, a 20GHz scope with TDR, able to characterize trace impedance absolutely workably for modern motherboard applications. I got a perfectly functioning one on ebay for $600. Also you can get the service manuals, which you can't for more recent equipment.
joezydeco 14y ago
Bunnie is taking advantage of the massive scale of these SoC systems like the i.MX. There really isn't a lot of exotic signal line design needed to make these chips run. From my own knowledge of board design with this Freescale part, the only tricky layout would be the DDR3 RAM lines. The rest is wiring up I/O to the necessary connectors and discretes. TI even made it easier by mounting their DRAM in package-on-package ball grid. You can find the TI OMAP4 Pandaboard schematics online and see how simple their system design is.
cdawzrd 14y ago
You don't need that kind of gear to build a board like this. You just need a good set of EDA tools and to read all the datasheets carefully. Stuff like trace impedance and the performance of high-speed lines should be done in simulation tools before you ever send out the board to be fabbed. It's only in cases where people are really pushing the limits (networking gear, RF gear, for example) that high-speed physical measurement hardware is necessary. A board like that, with a Spartan6 and ARM processor, is actually fairly easy to make work "out of the box" with minimal attention to pre-build simulation, as long as you carefully follow the datasheets' recommendations for signal routing, bypass, etc.

by JDuMond 14y ago

TerraHertz 14y ago

Actually it's been easily possible for years. Just forget about buying new equipment and buy older Tektronix or HP sampling scopes on ebay. For eg the HP 54121T, a 20GHz scope with TDR, able to characterize trace impedance absolutely workably for modern motherboard applications. I got a perfectly functioning one on ebay for $600. Also you can get the service manuals, which you can't for more recent equipment.

joezydeco 14y ago

Bunnie is taking advantage of the massive scale of these SoC systems like the i.MX. There really isn't a lot of exotic signal line design needed to make these chips run. From my own knowledge of board design with this Freescale part, the only tricky layout would be the DDR3 RAM lines. The rest is wiring up I/O to the necessary connectors and discretes. TI even made it easier by mounting their DRAM in package-on-package ball grid. You can find the TI OMAP4 Pandaboard schematics online and see how simple their system design is.

cdawzrd 14y ago

You don't need that kind of gear to build a board like this. You just need a good set of EDA tools and to read all the datasheets carefully. Stuff like trace impedance and the performance of high-speed lines should be done in simulation tools before you ever send out the board to be fabbed. It's only in cases where people are really pushing the limits (networking gear, RF gear, for example) that high-speed physical measurement hardware is necessary. A board like that, with a Spartan6 and ARM processor, is actually fairly easy to make work "out of the box" with minimal attention to pre-build simulation, as long as you carefully follow the datasheets' recommendations for signal routing, bypass, etc.