Due to a problem in the Intel® Quartus® Prime Pro edition software version 21.1, you may see incorrect results from your inferred RAM. This problem only affects inferred memories that use the RAMSTYLE = "no_rw_check" attribute. The incorrect data only occurs when reading from an address one clock cycle after it has been written to.
All designs that are affected have this warning reported during synthesis.
Warning (22231): RAM "<RAM_INSTANCE_NAME>" has all read-during-write behaviors changed to DONT_CARE due to the setting of the ramstyle attribute "no_rw_check"
This problem does not affect RAMs that are instantiated or RAMs that are inferred using 3rd party synthesis tools.
A patch is available to fix this problem for the Intel® Quartus® Prime Pro Edition software version 21.1
Download and install Patch 0.09 from the appropriate link below.
- Download patch Intel® Quartus® Prime Pro Edition 21.1 0.09 for Windows (.exe)
- Download patch Intel® Quartus® Prime Pro Edition 21.1 0.09 for Linux (.run)
- Download the Readme for Intel® Quartus® Prime Pro Edition 21.1 0.09 (.txt)
This problem is fixed starting with the Intel® Quartus® Prime Pro Edition software version 21.2.