Anybody added external SRAM to Kinetis K60 while using MQX.

grixk60n512 · ‎05-10-2013

Hi

Is anybody running MQX on a K60 processor with external SRAM?

Currently I am exhausting RAM, which manifests itself when TCP sockets are opened. Currently only have about 20K free when the application is running.

So the question is really how easy will it be to add external sram and make MQX aware/use it. (Also any idea if there is a performance hit?)

Regards

Gary

OliverSedlacek · ‎05-13-2013

Yes, I've done it. I'm the hardware guy, so I'm not up to speed with all the MQX issues, but basically we hung 1Mx16 SRAM on the Flexbus and used FB_CS3 to decode it. It works better if you don't mix up your BHE and BLE strobes. With 70nsec SRAM we needed 4 wait states with a 50MHz Flexbus clock, so there is a performance penalty. You haven't specified which K60 you are using as the subfamily 3 parts will cache the SRAM and the subfamily 2 parts wont.

I don't think the MQX bit was too difficult. I think you just need to edit your .icf and rebuild your BSP.

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OliverSedlacek · ‎05-13-2013

Yes, I've done it. I'm the hardware guy, so I'm not up to speed with all the MQX issues, but basically we hung 1Mx16 SRAM on the Flexbus and used FB_CS3 to decode it. It works better if you don't mix up your BHE and BLE strobes. With 70nsec SRAM we needed 4 wait states with a 50MHz Flexbus clock, so there is a performance penalty. You haven't specified which K60 you are using as the subfamily 3 parts will cache the SRAM and the subfamily 2 parts wont.

I don't think the MQX bit was too difficult. I think you just need to edit your .icf and rebuild your BSP.

grixk60n512 · ‎05-13-2013

Hi Oliver,

I'm the software guy :smileyhappy:, and I thought as much re : the changes to the linker file. Will pass on the info to the hardware guy.

Thanks a ton.

Gary