# I-type register format maximum size of a constant

The above picture is an I-type format register. I am confused as to why the largest constant possible is $$2^{15}$$ Should the largest possible constant be $$2^{16} -1$$

• Please can you edit your question and greatly improve it by details such as the CPU you're using and why. The better the quality of your question, the better the quality of the answers you will attract. – TonyM Mar 5 '18 at 22:39
• Just guessing: This might be a MIPS instruction. In that case, it's 2¹⁵-1 because the value is sign-extended, not zero-extended. (It is treated as a signed 16-bit integer) – Jonathan S. Mar 5 '18 at 22:47
• Yes, its a MIPS instruction – user3067059 Mar 5 '18 at 23:20