private long getMinPossibleValue(int bytes, boolean allowNegativeValues) {
		if (!allowNegativeValues) {
			return 0;
		}
		int bits = bytes * 8;

		// smallest value (largest negative) that can be stored in n bits is when the sign bit
		// is on (and sign extended), and all less significant bits are 0
		return -1L << (bits - 1);
	}
Database implementation for the enumerated data type.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/EnumDB.java