Patent ID: 8072831

Claim:
A fuse element reading circuit comprising: a first fuse element having a resistance that differs in accordance with whether the first fuse element is in a blown state or an unblown state; a reference voltage output circuit unit that outputs a reference voltage which differs in accordance with a normal mode or a test mode; and a voltage comparison circuit unit that compares a read voltage corresponding to the resistance of the first fuse element with the reference voltage output from the reference voltage output circuit unit; wherein the test mode is an unblown fuse element test mode or a blown fuse element test mode; wherein the reference voltage for the normal mode is higher than the reference voltage for the unblown fuse element test mode and is lower than the reference voltage for the blown fuse element test mode; wherein the reference voltage output circuit unit outputs a reference voltage corresponding to a resistance of a series connection circuit including unblown second fuse elements connected in series in the normal mode, outputs a reference voltage corresponding to a resistance of a series connection circuit including unblown third fuse elements connected in series in the unblown fuse element test mode, and outputs a reference voltage corresponding to a resistance of a series connection circuit including unblown fourth fuse elements connected in series in the blown fuse element test mode, and wherein the number of series connections in the series connection circuit, including the second fuse elements connected in series, is greater than the number of series connections in the series connection circuit, including the third fuse elements connected in series, and is smaller than the number of series connections in the series connection circuit, including the fourth fuse elements connected in series.