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FX2LP unable to access more than 8kB RAM
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FX2LP unable to access more than 8kB RAM

kmalkki posted on 03 Sep 2012 5:55 AM PST
Member
4 Forum Posts

I have purchased three FX2LP development boards for hobby use from e-bay. These are sold as:

EZ-USB FX2LP CY7C68013A USB Development Core Board Logic Analyzer EEPROM

Any documentation I find says these chips have 16kB RAM, but I can only access bottom 8kB, the range 0x0000 to 0x1fff. Any writes to RAM region 0x2000 to 0x3fff are ignored. Reads seem to return back the same 16bit value for any address. This happens with both 0xA0 vendorcode over USB and executing 8051 program code.

If my build toolchain places descriptors at over 0x2000, the device will disconnect and renumerate, but fails to setup USB with new descriptors. Same code with descriptors moved below 0x2000 works as expected.

Markings on the boards and chips I have:

LCSOFT CY7C68013A MINI BOARD

CY7C68013A-56PVXC
B 04 PHI 1125
CYP 631702

Can you tell if these markings are valid for Cypress manufactured chips and if there is any related errata with the revision?

Is there some (un)documented bootstrap that could explain this behaviour?
 




Re: FX2LP unable to access more than 8kB RAM

kmalkki posted on 04 Sep 2012 04:49 AM PST
Member
4 Forum Posts

After discussion and feedback from other users, I have come to the conclusion the chips are relabeled FX2 parts.



Re: FX2LP unable to access more than 8kB RAM

aasi posted on 04 Sep 2012 09:36 AM PST
Cypress Employee
1090 Forum Posts

 Create a tech support case and provide the marking details. Our packaging team should be able to track and tell if these are actual valid parts or from the grey market.

Regards,

Anand



Re: FX2LP unable to access more than 8kB RAM

kmalkki posted on 06 Sep 2012 10:49 PM PST
Member
4 Forum Posts

The package labelling I posted above already.

I have now verified chips respond with REVID=04, indicating FX2 rev E.

 



Re: FX2LP unable to access more than 8kB RAM

Gayathri posted on 10 Sep 2012 01:49 AM PST
Cypress Employee
428 Forum Posts

Hi,

 

Please create a tech support case at www.cypress.com. The issue can be further discussed and figured out through that.

 

Regards,

Gayathri 






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