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FX3 Slave FIFO Buffer Size
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FX3 Slave FIFO Buffer Size

wglados posted on 18 Apr 2012 11:38 AM PST
Top Contributor
23 Forum Posts

 

Hey all -

 

How does buffer space work in the FX3 for Slave FIFO mode?  Are buffers allocated per physical thread, or per logical socket?

 

How much buffer space is there total for Slave FIFO?  If I use four physical threads, with only one socket per thread, how much buffer space does each physical thread have?  If I attach 2 logical sockets to each physical thread, does each logical socket now only have half as much space?




Re: FX3 Slave FIFO Buffer Size

aasi posted on 19 Apr 2012 03:17 AM PST
Cypress Employee
1073 Forum Posts

The RAM is shared by both code and buffer. So the amount of buffer that you can use depends on the firmware size and how you configure the buffer for the DMA channel.

Regards,

Anand



Re: FX3 Slave FIFO Buffer Size

wglados posted on 19 Apr 2012 09:38 AM PST
Top Contributor
23 Forum Posts

  Aasi -

 

Thank you for the response.  Can you answer one more question then:

 

When you configure the buffer size, how does the 'buffer count' value passed into the DMA configuration struct map to actual memory?  If I set dma_config.count = 2, and thus allocate 2 buffers to that DMA channel, how much memory is that?



Re: FX3 Slave FIFO Buffer Size

wglados posted on 20 Apr 2012 10:42 AM PST
Top Contributor
23 Forum Posts

 Anand -

 

Do you have any documentation on how setting the buffer count in the DMA configuration maps to memory?



Re: FX3 Slave FIFO Buffer Size

bhilburn posted on 20 Apr 2012 05:06 PM PST
Member
5 Forum Posts

 I'm going to keep bumping this until I get a response from Cypress.



Re: FX3 Slave FIFO Buffer Size

wglados posted on 23 Apr 2012 09:11 AM PST
Top Contributor
23 Forum Posts

 Anand -

 

Bump!



Re: FX3 Slave FIFO Buffer Size

bhilburn posted on 23 Apr 2012 10:05 AM PST
Member
5 Forum Posts

 Okay, I figured it out.

 

Buffer sizes are configured by the 'size' parameter in DMA config, and then you tell each DMA config how many buffers they get.

 

Now, 'thread stack size' is still a total mystery.






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