Semiconductor device
First Claim
1. A semiconductor device comprising:
- a shift register comprising a plurality of stages, each of the plurality of stages comprising a flipflop,wherein in each of the plurality of stages, the flipflop comprises a first memory circuit, a second memory circuit and a third memory circuit,wherein in each of the plurality of stages, the second memory circuit is configured to save data of the first memory circuit, write data of the first memory circuit to the third memory circuit and write data of the third memory circuit to the first memory circuit,wherein the third memory circuit of each of stages other than a last stage among the plurality of stages is configured to transfer the data to the third memory circuit of a next stage, andwherein in each of the plurality of stages, each of the second memory circuit and the third memory circuit is configured to hold data in a period during which power supply to the flipflop is stopped.
1 Assignment
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Accused Products
Abstract
A register for a scan test has a data saving function. A scan flipflop includes first to third memory circuits. The first memory circuit is a memory circuit functioning as a register of a combination circuit in normal operation. The second memory circuit is a memory circuit for backup of the first memory circuit. The third memory circuit has a function of transferring data to a flipflop in a next stage. Further, the second memory circuit has a function of writing data of the first memory circuit to the third memory circuit and a function of writing data of the third memory circuit to the first memory circuit. At a given time, data of the first memory circuit can be extracted from an external device and data can be stored in the first memory circuit from an external device.
207 Citations
17 Claims
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1. A semiconductor device comprising:
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a shift register comprising a plurality of stages, each of the plurality of stages comprising a flipflop, wherein in each of the plurality of stages, the flipflop comprises a first memory circuit, a second memory circuit and a third memory circuit, wherein in each of the plurality of stages, the second memory circuit is configured to save data of the first memory circuit, write data of the first memory circuit to the third memory circuit and write data of the third memory circuit to the first memory circuit, wherein the third memory circuit of each of stages other than a last stage among the plurality of stages is configured to transfer the data to the third memory circuit of a next stage, and wherein in each of the plurality of stages, each of the second memory circuit and the third memory circuit is configured to hold data in a period during which power supply to the flipflop is stopped. - View Dependent Claims (2)
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3. A semiconductor device comprising:
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a shift register comprising a first stage and a second stage, each of the first stage and the second stage comprising a flipflop, wherein in each of the first stage and the second stage, the flipflop comprises a first memory circuit, a second memory circuit and a third memory circuit, wherein in each of the first stage and the second stage, the first memory circuit comprises a first data holding portion, a first input terminal and a first output terminal, wherein in each of the first stage and the second stage, the first memory circuit is configured to store data input from the first input terminal to the first data holding portion and output the data stored in the first data holding portion from the first output terminal, wherein in each of the first stage and the second stage, the third memory circuit comprises a second data holding portion, a second input terminal and a second output terminal, wherein the second output terminal of the third memory circuit of the first stage is electrically connected to the second input terminal of the third memory circuit of the second stage, wherein in each of the first stage and the second stage, the third memory circuit is configured to store data input from the second input terminal to the second data holding portion and output the data stored in the second data holding portion from the second output terminal, wherein in each of the first stage and the second stage, the second memory circuit is configured to store the data stored in the first data holding portion to the second data holding portion and store the data stored in the second data holding portion to the first data holding portion, and wherein in each of the first stage and the second stage, each of the second memory circuit and the third memory circuit is configured to hold the data in the second data holding portion in a period during which power supply to the flipflop is stopped. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11)
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12. A semiconductor device comprising:
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a shift register comprising a first stage and a second stage, each of the first stage and the second stage comprising; a first data holding portion comprising; a first node; and a second node; a second data holding portion comprising; a third node; and a fourth node; a first transistor; a second transistor; a third transistor; a fourth transistor; a fifth transistor; and a sixth transistor, wherein in each of the first stage and the second stage, a gate of the first transistor is connected to the first node, wherein in each of the first stage and the second stage, a gate of the second transistor is connected to the second node, wherein in each of the first stage and the second stage, one of a source and a drain of the first transistor is connected to the third node, wherein in each of the first stage and the second stage, one of a source and a drain of the second transistor is connected to the fourth node, wherein in each of the first stage and the second stage, one of a source and a drain of the third transistor is connected to the first node, wherein in each of the first stage and the second stage, one of a source and a drain of the fourth transistor is connected to the second node, wherein in each of the first stage and the second stage, a gate of the third transistor is connected to the third node, wherein in each of the first stage and the second stage, a gate of the fourth transistor is connected to the fourth node, wherein in each of the first stage and the second stage, a gate of the fifth transistor is connected to the third node, wherein in each of the first stage and the second stage, one of a source and a drain of the fifth transistor is connected to the fourth node, wherein in each of the first stage and the second stage, a gate of the sixth transistor is connected to the fourth node, and wherein one of a source and a drain of the sixth transistor of the first stage is connected to the third node of the second stage. - View Dependent Claims (13, 14, 15, 16, 17)
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Specification