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Describe CVA6 for write-through and write-back cache versions

Open MikeOpenHWGroup opened this issue 4 years ago • 1 comments

In #602, there was a conversation like this:

Is the list of files in the manifest complete?

Looks okay for the write-through cache version. Of course, the write-back cache needs different files.

AFAICT, the ability to compile CVA6 for either write-through and write-back cache versions is not described in the User Manual. The User Manual should be updated to explain:

  1. How to compile the CVA6 for write-through and write-back cache versions.
  2. Theory of operation for the write-through cache controller.
  3. Theory of operation for the write-back cache controller.

MikeOpenHWGroup avatar Feb 01 '21 13:02 MikeOpenHWGroup

  1. How to compile the CVA6 for write-through and write-back cache versions.

For an FPGA emulation (say for example, using the Genesys 2 board) can we enable the write-back cache by simply commenting out the `define WT_DCACHE line in the genesysii.svh file?

It seems as though the WB_DCACHE define is not mentioned anywhere else in the source code, so I'm assuming we don't need to uncomment that line.

j-silv avatar Feb 26 '22 12:02 j-silv

@j-silv yes, by default the write-back cache is selected; you have compile the design with WT_DCACHE defined if you want to use a write-through cache

suppamax avatar Nov 08 '22 10:11 suppamax

We've just published our notes about the WB cache. And here's an interesting paper about the WT cache.

Hope it helps

suppamax avatar Nov 08 '22 10:11 suppamax

Hi @JeanRochCoulon, this is an old issue with new information. Let's get this into the User Manual.

MikeOpenHWGroup avatar Feb 17 '23 17:02 MikeOpenHWGroup

I agree. The cache type should be addded in the CVA6 parameter chapter of user manual. I take the point !

JeanRochCoulon avatar Mar 14 '23 08:03 JeanRochCoulon

Hi, I have just merged the #1127 to replace the define by a localparam into the config pkg. On my side, the issue is solved. Mike, up to you to take the decidsion to close the issue.

JeanRochCoulon avatar Mar 21 '23 13:03 JeanRochCoulon

Thanks everyone! Closing.

MikeOpenHWGroup avatar Mar 23 '23 16:03 MikeOpenHWGroup