| 摘要 |
PURPOSE:To attain programming in a system using only a 5V power supply and to enhance the usefulness by providing a control function on a high voltage power supply for writing the program. CONSTITUTION:A boosting circuit 3 boosts a 5V input to 20V based on the clock of a ring oscillator OSC 1. A multiplexer 20 gives a 20V to a W-gate controller 5 since the input is less than 20V and it represents no signal from a detector 2. An address decoder 6 designates the address of a memory cell 7 based on a serial address signal. A program by a serial data signal SDATA synchronously with a shift clock SCLK is given to the controller 5 and stored in a built-in shift register. The information SDATA is fed to the memory cell 7. A strobe signal NSTB is given to the controller 5 at the end of one unit of input of program information and one unit input is written to the prescribed address of the memory cell. By such constitution, the programming is optionally attained in the state of on-board or before or after the on-board. |
