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ide to usb controller - HD rack :)

Hello Engineers! :)

I am interested about making a hard disk rack...ie connecting about eight hard disks simultaneously to a personal computer via the usb port. I think the second part is easy, just make eight ide to usb controllers and connect them to a usb hub.

Any proposals about the structure of the project? Or where I can find any information, schematics, *reference* for these protocols and interconnections? Is is possible to use an ATMega or is it better to use a Cyclone FPGA?

I don't want to take a ready-made solution...and this is the only think Google and newsgroups return!

Thank you again!

Reply to
starchild
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USB.org will get you to the protocol for disk-type devices.

Well... do you care about performance? All the ATmegas with USB interfaces are USB 1.1 (12Mbps), whereas you *might* have a shot at getting USB 2.0 (480Mbps) speeds out of an FPGA... but probably not with the cheaper/slower speeds grades. (Traditionally this problem was solved with a "SerDes" that would do the high-speed serialization/deserialization for you and present and accept parallel data at a much lower clock rate, but AFAIK such ICs don't exist for USB 2.0.)

This is a very large project you're undertaking, if you insist on doing it "from scratch" don't have prior experience interfacing to USB or hard drives. You're talking many months of effort here...

What's your goal? To learn about USB? Hard drive interfacing?

---Joel

Reply to
Joel Kolstad

For implementation reference:

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you can find sources for the usb/ide chips and usb hub chips easy enough I suppose if you want to get it all on one board instead of stringing usb cables around the chassis

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or

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has everything you need for IDE and USB on FPGA/CPLD... that will leave you with integrating an MCU core and writing the code to make it functional. you could expose individial drives or make a USB/IDE raid controller.

Reply to
John Barrett

As I understand it USB has a maximum 4-way fanout per hub so you'll need three hubs to get one usb cable to 8 drives it's probably possible to put all three hubs on a single chip

have you considered using SATA instead of IDE, you could use SATA instead of USB too for that matter....

start adding "datasheet" or "schematic" to your searches

Bye. Jasen

Reply to
jasen

I didn't have examined the SATA solution. I think it gives more expandibility...though I have to do a research about the protocol. Thank you all for your replies, I will have more news soon! :)

Reply to
starchild

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