Semiconductor device
AssigneeFujitsu Limited
InventorKenichi Kawasaki
Life of this patent
Estimating the term…
Abstract
A first power-cutoff switch is disposed between a power line and an internal power line dedicated for a circuit block, and has a current supply capacity having the level at which ON-current can protect an external examination environment. A second power-cutoff switch is disposed between a power line and an internal power line, and has a current supply capacity having the level at which ON-current can supply consumed current of the circuit block. A detecting circuit detects that a voltage of the internal power line matches a reference voltage. The first power-cutoff switch is ON/OFF by an operation state of the circuit block. The second power-cutoff switch is ON by detecting the matching of the volumes with the detecting circuit and is OFF by the ON/OFF operation of the first power-cutoff switch.
Claims11
A semiconductor device comprising:
- a first power line and a second power line;
- a circuit block connected to the second power line to receive a power supply voltage;
- a first switch connected between the first power line and the second power line;
- and
- a second switch connected between the first power line and the second power line,
- wherein the first switch is off in a normal operation mode and is on in a test mode, and
- the second switch is off in the test mode, and
- an operation state of the circuit block is on or off in the normal operation mode by on or off operation of the second switch.
A semiconductor device comprises:
- a first power line and a second power line;
- a circuit block connected to the second power line to receive a power supply voltage;
- a first switch connected between the first power line and the second power line, the first switch being capable of tuning on or off in dependence on a state of operation of the circuit block;
- a capacitor connected to the second power line;
- and
- a second switch being on by an off operation of the first switch and discharging charges stored in the capacitor in a test mode.
A semiconductor device comprising:
- a first power line and a second power line;
- a circuit block connected to the second power line to receive a power supply voltage;
- a first switch connected between the first power line and the second power line;
- and
- a second switch connected between the first power line and the second power line;
- wherein
- the first switch is on in a test mode;
- the second switch is off in the test mode;
- and
- an operation state of the circuit block is on or off in a normal operation mode by an on or off operation of the second switch.
Dependencies are inferred from the claim text.