| 摘要 |
PURPOSE:To attain an interface without providing an exclusive terminal by providing a switching circuit between all control signal terminals in a microcontroller and an interface circuit for an evaluation chip. CONSTITUTION:Since a signal switching circuit 5 is functioned as a reference I/O terminal by a mode signal inputted from a mode terminal 7 in a controller mode, the circuit 5 connects an address/data bus 9, a control signal line 10 for a peripheral circuit, etc., to an I/O interface circuit 6. In a supporting device mode, the circuit 5 switches the signal line of the circuit 6 so as to be functioned as an evaluation chip CPU status signal terminal. Since the function of the terminal is switched by allowing the mode specifying terminal to set up the supporting device mode, interface with the evaluation chip 17 can be attained without increasing the number of mass-produced terminals. |
