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424 Discussions

How OpenCL SDK memory access code is mapped to SDRAM ?

RElna
Beginner
301 Views

Hi,

I was wondering if someone can guide me on how opencl sdk operations are mapped to memory. For example, if we define a global buffer input data variable, would this be mapped to SDRAM or FPGA RAMs ?

 

Also, if it is mapped to SDRAM, which interconnect is used for the connection (e.g., FPGA-to-HPS SDRAM or FPGA-to HPS bridge ?

 

How can we differentiate and specify these connections ?

 

Thanks

Rana

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3 Replies
HRZ
Valued Contributor II
143 Views

Global buffers are mapped to the FPGA on-board DDR memory. All other buffers are mapped to either Block RAMs or registers depending on their size and access pattern.

 

Maybe someone else can answer your second question.

RElna
Beginner
143 Views

Thanks for your reply. Can you guide me to a reference where I can read more about the mappings ? I have searched online a lot and I could not find a definite answer.

 

I also would like to know how to access HPS SDRAM from the opencl code.

 

 

 

HRZ
Valued Contributor II
143 Views

I remember the mapping was mentioned in the guides before but I cannot seem to find it anymore. You can check the following tutorial from Intel, though:

 

https://www.youtube.com/watch?v=1zGpN28mXN4

 

And the main OpenCL guides can be found here:

 

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/opencl-sdk/aocl-best-pra...

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/opencl-sdk/aocl_programm...

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