Semiconductor device, unique ID of semiconductor device and method for verifying unique ID
The present invention relates to a semiconductor device, a unique ID of the semiconductor device and a method for verifying the unique ID. Thus, original data (bit string) having 127-bit length [ 126:0 ] is inputted at step S 1 . Then, it is determined whether the number of bits of “1” in the bit string [ 126:0 ] inputted at the step S 1 is more than the half of the bits of the bit string (that is, not less than 64) or not at step S 2 . When the number is not less than 64, the process proceeds to step S 3 . At the step S 3 , the bit string [ 126:0 ] is inverted and an invert bit [ 127 ] is set to “1”. Then, the process proceeds to step S 5 . At the step S 5 , the fuse corresponding to the bit string [ 126:0 ] and the bit [ 127 ] are cut by LT.
1. A semiconductor device having a unique ID that is uniquely set, the semiconductor device comprising:
a nonvolatile storage unit; and
a processing unit,
wherein said unique ID is stored in said nonvolatile storage unit,
wherein said stored unique ID comprises unique chip information containing information at the time of manufacturing of said semiconductor device and an inspection bit provided by executing a cyclic redundancy checking operation for said chip information,
wherein said processing unit, checks the numbers of logical “0s” and “1s” in a bit stream indicating the unique chip information, bit inverts said bit stream when said number of the logical “1s” is more than a predetermined number, and stores said bit stream or bit inverted bit stream into the nonvolatile storage unit, and
wherein said processing unit uses said stored unique ID in an unmodified form when the usage of said stored unique ID ensures the uniqueness, and bit inverts the stored unique ID when a current unique ID is equal in value to said stored unique ID being used,
wherein said semiconductor device comprises a plurality of fuses as said nonvolatile storage unit, and said stored unique ID of the semiconductor device is recorded in said semiconductor device by forming a cut state and an uncut state of said plurality of fuses, and,
wherein said chip information comprises at least a lot number at the time of manufacturing of said semiconductor device, a wafer number of a wafer on which said semiconductor device is formed, a chip position specifying a position of said semiconductor device on said wafer, and a manufacturing date.
2. The unique ID of the semiconductor device according to claim 1 , wherein
said chip information defines each information by incrementing binary data regularly, and
a unit of said incrementing is other than 2 n (n=0, 1, 2, . . . ) in decimal form.