Title:
SEMICONDUCTOR DEVICE
Document Type and Number:
Japanese Patent JP3184101
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a semiconductor device that can switch the operating mode without providing a testing terminal and act stably at the time of both normal operation and testing without generating an unstable area even though switching the operating mode.
SOLUTION: A first circuit 3 and a second circuit 10 are driven respectively by a first power source 1 and a second power source 2. At the time of normal operation, the second power source 2 is set to operating potential. When an operating mode switching circuit 5 supplies an internal logic circuit 14 with a signal of an input terminal 6 sent through an input buffer 7, operation to be an original object is performed in the internal logic circuit 14, and its result is outputted to an output terminal 8 through a selector 18 and an output buffer 9. At the time of testing, on the other hand, the second power source 2 is set to earth potential. The operating mode switching circuit 5 by-passes the internal logic circuit 14 and sends the output of the input buffer 7 directly to the output buffer 9 through the selector 18 so as to be outputted from the output terminal 8.
Inventors:
High Shiga Suga
Application Number:
JP23707796A
Publication Date:
July 09, 2001
Filing Date:
September 06, 1996
Export Citation:
Assignee:
NEC IC Microcomputer System Co., Ltd.
International Classes:
G01R31/3185; G01R31/28; (IPC1-7): G01R31/28
Domestic Patent References:
| JP3175383A |
Attorney, Agent or Firm:
Nobuo Takahashi (3 outside)