| 摘要 |
PURPOSE:To provide an economic system which contains an integrated circuit by providing therein a controller which can immediately write by the application of a PROM write voltage by switching PROM write mode and a logic circuit mode, thereby performing a simple PROM control system. CONSTITUTION:The output 10 of a latch circuit 5 is connected with a connecting pad 11 for connecting the terminal of a LSI package with a substrate, and the pad 11 is switched to an input or output mode by the output 10. In order to updata the information of an EPROM circuit 8, the information is erased by ultraviolet rays, a write voltage is supplied to a write power supply terminal VPP, and address and data are applied from the pad 11. When the information of the circuit 8 is erased, the ultraviolet rays are emitted simultaneously to the memory circuit 2 integrated on the same substrate, the information (the information that the information is written in the circuit 8) of a nonvolatile memory cell Tr1 is also erased, and the cell Tr1 can always store the state of the circuit 8. |
