ID:13651 VHDL Attribute warning at <location>: encodings in ENUM_ENCODING or SYN_ENCODING attribute must have the same length

CAUSE: In an attribute specification at the specified location in a VHDL Design File (.vhd), you specified the ENUM_ENCODING or SYN_ENCODING attribute for an enumeration type object. However, the expression in the attribute specification contains encodings of different lengths. For example, in the following attribute specification, the encoding "1" is smaller than the encodings "01", "10", and "00":

ATTRIBUTE ENUM_ENCODING OF count_state: TYPE IS "1 01 10 00"

All the encoding values in an attribute expression must be the same length. As a result, Quartus Prime Integrated Synthesis ignored all the encoding values in the expression.