| 摘要 |
PURPOSE:To obtain a PROM writing circuit using a low writing current by writing data in the PROM every bit to reduce a peak current at the writing time. CONSTITUTION:An input data signal 1, a writing signal 2 and a write permitting signal 13 are inputted to each three-input NOR gates 7. The output 14 of the NOR gate 7 is written in a PROM cell 6 selected by a data decoder 5 through a selector 4. Only the write permitting signals 13 corresponds to bits 1-n respectively. Namely, the input data signal 1 is impressed during the writing signal 2 is turned on and the write permitting signals 13 corresponding to the bits 1-n are generated with time division. Since the peak current at the writing time is reduced, the PROM writing circuit using the low writing current can be obtained. |
