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DMA buffer size
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DMA buffer size

hcshin posted on 06 Oct 2011 6:12 AM PST
Senior Member
14 Forum Posts

Dear forum members,

 

I experimented bulk transfer speed with DMA buffer 32KB and 16 burst endpoint, and I got a speed 262MB/s.

 

What is the relation between DMA buffer size and burst size?

 

Is there any delay at buffer changing time? If not, I think CyUSB driver can't manipulate DMA machanism efficiently.

 

Best Regards,

HC

Re: DMA buffer size

aasi posted on 09 Oct 2011 12:44 PM PST
Cypress Employee
1073 Forum Posts

Hi,

I didn't quite understand your question with regards to the buffer changing and DMA manipulation of CyUSB.sys.

Which buffer changing are you talking about? on the host side or device side?

Regards,

Anand

Re: DMA buffer size

hcshin posted on 10 Oct 2011 02:11 AM PST
Senior Member
14 Forum Posts

Hi Anand,

I changed device side buffer size up to 48KByte.

and buffer size seems to be set up to 64K-1 byte. Right?

Another question, If an CRC error occured at bulk transfer, do the firmware and PC driver handle this error automatically?

Regards,

HC

 



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