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ide to usb controller - HD rack :)

S

starchild

Jan 1, 1970
0
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!
 
J

Joel Kolstad

Jan 1, 1970
0
starchild said:
Any proposals about the structure of the project? Or where I can find
any information, schematics, *reference* for these protocols and
interconnections?

USB.org will get you to the protocol for disk-type devices.
Is is possible to use an ATMega or is it better to
use a Cyclone FPGA?

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

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

---Joel
 
J

John Barrett

Jan 1, 1970
0
starchild said:
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!

For implementation reference:

http://www.lvr.com/usbms.htm

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

http://atmel.com/dyn/resources/prod_documents/doc1137.pdf
http://www.lvr.com/usbchips.htm

or

http://www.opencores.org 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.
 
J

jasen

Jan 1, 1970
0
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?

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

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

Bye.
Jasen
 
S

starchild

Jan 1, 1970
0
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 ofIDE, you could use SATA instead of
USB too for that matter....


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

Bye.
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! :)
 
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