| 摘要 |
PURPOSE:To design an interface with a peripheral circuit without receiving a restraint concerning the use of a terminal by sharing a terminal for a program power source for writing and reading an EPROM with a terminal for a test. CONSTITUTION:A microcomputer 1 builds in an EPROM, has a power source terminal Vcc, a resetting releasing terminal RESET, an input/output port I/O, input terminals I0, I1-I3 of a control signal port and test/program power source terminals TEST/Vpp as a mode switching terminal and a crystal oscillator 2 is connected. Here, a test/program power source terminal TEST/Vpp as a mode switching terminal shares the terminal function for a test and the terminal function for a program power source. Thus, without receiving a restraint concerning the terminal use at the time of using as a microcomputer mode with a user, the interface with a peripheral circuit can be designed. |
