Semiconductor device suppressing BTI deterioration
Disclosed herein is a device includes a command generation circuit that activates first and second command signals, an internal circuit that includes a plurality of transistors that are brought into a first operation state when at least one of the first and second command signals is activated, and an output gate circuit that receives a first signal output from the internal circuit, the output gate circuit being configured to pass the first signal when the second command signal is deactivated and to block the first signal when the second command signal is activated.
1. A semiconductor device comprising:
a command generation circuit that activates first and second command signals;
an input gate circuit that receives the first command signal and a command, the input gate circuit configured to pass the command when the first command signal is deactivated and block the command when the first command signal is activated;
an internal circuit coupled to the input gate circuit and the internal circuit includes a plurality of transistors that are brought into a first operation state when at least one of the first and second command signals is activated; and
an output gate circuit that receives a first signal output from the internal circuit, the output gate circuit being configured to pass the first signal when the second command signal is deactivated and to block the first signal when the second command signal is activated.
2. The semiconductor device as claimed in claim 1 , wherein the internal circuit is configured such that the plurality of transistors are brought into a second operation state different from the first operation state when both the first and second command signals are deactivated.
3. The semiconductor device as claimed in claim 1 , further comprising a second control circuit, wherein
the internal circuit and the output gate circuit constitute a first control circuit,
the first control circuit is configured to perform a first control by outputting the first signal from the output gate circuit when the first command signal is activated, and not to perform the first control when the second command signal is activated, and
the second control circuit is configured to perform a second control different from the first control when the second command signal is activated.
4. The semiconductor device as claimed in claim 3 , wherein
the second control circuit is configured to activate a third command signal in response to an activation of the second command signal, and
the internal circuit is configured such that the plurality of transistors are brought into the first operation state when at least one of the first and third command signals is activated.
5. The semiconductor device as claimed in claim 4 , wherein
the second command signal is activated periodically,
the second control circuit is configured to activate the third command signal each time the second command signal is activated, and
a period during which activation of the third command signal continues is shorter than an activation cycle of the second command signal.
6. The semiconductor device as claimed in claim 4 , wherein the input gate circuit outputs a second signal taking a first logic state when at least one of the first and third command signals is activated and taking a second logic state when neither the first nor the third command signal is activated, wherein
the internal circuit includes plural stage of inverter circuits,
the plurality of transistors constitute the plural stage of inverter circuits, and
the second signal is supplied to an input terminal of an inverter circuit being an initial stage of the plural stage of inverter circuits.
7. A semiconductor device comprising:
a command generation circuit that activates first and second command signals;
an internal circuit that includes a plurality of transistors that are brought into a first operation state when at least one of the first and second command signals is activated;
an output gate circuit that receives a first signal output from the internal circuit, the output gate circuit being configured to pass the first signal when the second command signal is deactivated and to block the first signal when the second command signal is activated,
wherein the internal circuit and the output gate circuit constitute a first control circuit, and the first control circuit is configured to perform a first control by outputting the first signal from the output gate circuit when the first command signal is activated, and not to perform the first control when the second command signal is activated; and
a second control circuit configured to perform a second control different from the first control when the second command signal is activated,
wherein the second control circuit is configured to activate a fourth command signal in response to an activation of the second command signal, and
an output of the output gate circuit is fixed to a constant value when the fourth command signal is activated.
8. The semiconductor device as claimed in claim 3 , further comprising a plurality of memory cells that are arranged in a matrix pattern and are selected by row access and column access, wherein
the first control is of the column access, and
the second control is of the row access.
9. The semiconductor device as claimed in claim 8 , wherein
the first control is read control or write control for the plurality of memory cells, and
the second control is refresh control for the plurality of memory cells.
10. The semiconductor device as claimed in claim 1 , wherein
the internal circuit includes plural stage of inverter circuits, and
the plurality of transistors constitute the plural stage of inverter circuits.