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pwb
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Registered: ‎06-14-2012

data width converter - how to get 64 bit data from AXI 32 bit read

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Hi there. I have a general question. In a system where the slave data is 64 bits wide and I want to read it, Vivado does the data width conversion down to 32 bits. (Inserts the data width converter) Now, in the actual c code running on the embedded Arm, to read the full 64 bits do I need two read statements or does the AXI bus somehow know that it must transfer two 32 bit values? If two read statements are needed in the code, is the second one at the next address?

Thanks for any help or information.

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pwb
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Observer
5,764 Views
Registered: ‎06-14-2012
Yup.
A 'long long' pointer set to the address worked.

thanks...

View solution in original post

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Anonymous
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define a pointer of type "long long" in "C". Any reads to that will be taken care. You do not need to make two accesses.

 

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pwb
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Observer
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Registered: ‎06-14-2012

Thanks, I'll give it a try and post back with the results.

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pwb
Observer
Observer
5,765 Views
Registered: ‎06-14-2012
Yup.
A 'long long' pointer set to the address worked.

thanks...

View solution in original post

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1,229 Views
Registered: ‎01-24-2019

I have similar problem, but my FIFO is 128 bits(16 bytes) datawidth. How can I read the 128 bit(16byte) data? thanks.

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