METHOD AND APPARATUS TO MONITOR CIRCUIT VARIATION EFFECTS ON ELECTRICALLY PROGRAMMABLE FUSES

A monitor bank consists of test one time programmable memory that is programmed distinctively from functional one time programmable memory in order to determine whether the functional one time programmable memory has or will program successfully. In a specific embodiment, each monitor bank consists of a first eFuse configured to expectedly never blow, a second eFuse configured to expectedly always blow, and at least a third eFuse configured to be more difficult to blow than the first eFuse, but easier to blow than the second eFuse. The method of determining whether functional eFuses have or will be programmed successfully is described: programming a monitor bank; sensing whether the test eFuses have blown; creating a monitor bank bit line blow pattern; determining an anticipated bit line blow pattern; comparing the two patterns; and determining that the functional eFuses will not blow successfully if the patterns do not match.