From e4eaa5035458fbaf08de037d9382945b7c1f3aba Mon Sep 17 00:00:00 2001 From: Jerry Zhao Date: Tue, 13 Jun 2023 00:57:56 -0700 Subject: [PATCH] docs: Fix comment on rocc tag bits --- docs/Customization/RoCC-Accelerators.rst | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/docs/Customization/RoCC-Accelerators.rst b/docs/Customization/RoCC-Accelerators.rst index a2d98589..ad3bfa54 100644 --- a/docs/Customization/RoCC-Accelerators.rst +++ b/docs/Customization/RoCC-Accelerators.rst @@ -88,7 +88,8 @@ In your ``LazyRoCCModuleImp``, the signal ``io.mem`` is a ``HellaCacheIO``, whic At a high level, you must tag requests that you send across this interface using the ``io.mem.req.tag``, and the tag will be returned to you when the data is ready. Responses may come back out of order if you issue multiple requests, so you can use these tags to tell what data came back. -Note that the top two bits of the tag are reserved, and MUST be set to zero, or the interface will exhibit undefined behavior. +Note that the number of tag bits is controled by ``dcacheReqTagBits``, which is usually set to 6. +Using more than 6 bits will cause errors or hangs. Adding RoCC accelerator to Config