| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a high-voltage generation mehtod in which the time required for an erase operation and a programming operation is optimized and whose reliability and performance are enhanced by a method wherein the starting level of a high voltage is optimized in the erase operation and the programming operation. SOLUTION: A trimming counter 202 and a trimming encoder 203 act as a loop number-of-times counting circuit, for output of a level control signal, in order to supply an erase voltage of a programming voltage so as to be increased from a starting level whenever in erase operation and a programming operation are repeated. The counter 202 receives a program loop pulse OSP for counting of the number of times of the programming operation. In addition, a trimming address register 201 is installed, and it receives an address which is applied via an address buffer 10. The register 201 comprises many fuse elements which can be blown, it outputs, to the loop number- of-times counting circuit, a trimming signal for change of the starting level so as to respond to the address in a test, it selects and blows the fuse elements on the basis of a test result, it fixes a triming signal, and it sets the optimum starting level of the erase time and the programming time.</p> |
