Error(271011): Can't make global setting DUPLICATE_REGISTER using ALTERA_ATTRIBUTE

Description

Due to a problem in the Intel® Quartus® Prime Pro Edition Software version 19.1, the message above might be seen when using the manual register duplication (DUPLICATE_REGISTER) feature as a 'altera_attribute' synthesis attribute.

Resolution

To work around this problem, set the DUPLICATE_REGISTER assignment in the Intel® Quartus® Prime Software settings file (.qsf).

set_instance_assignment -name DUPLICATE_REGISTER -to <register_name> <num_duplicates>