Data holding apparatus and data read out method
AssigneeRohm Co., Ltd.
InventorYoshikazu Fujimori
Life of this patent
Estimating the term…
Abstract
A data holding device is provided that is capable of holding data even if the power supply is shut off and reliability in holding data is high. The data holding device 1 is provided with a data latch circuit 3 and a ferroelectric memory section 5. Ferroelectric capacitors 17 and 19 are capable of storing data in non-volatile manner. One end of the ferroelectric capacitor 17 is connected to the input node 7a of an inverter circuit 7 through a transfer gate 11. The transfer gate 11 is in the off state when data are passed. Therefore, even if input data D changes when data are passed, the change is quickly transmitted to the input node 7a, so that reliability of latching operation does not lower even if the operation is made at usual speeds.
Claims20
A data holding device with a data holding circuit made to be capable of holding data by interconnecting, in a series loop, an inverter circuit disposed in a main signal path and an inverter circuit disposed in a feedback path, comprising:
- a first on-off gate disposed between an output node of the inverter circuit disposed in the feedback path and an input node of the inverter circuit disposed in the main signal path, the first on-off gate being on-off-controlled to be on when data is held, and to be off when data is passed;
- and
- a first ferroelectric capacitor having its one end connected to the output node of the inverter circuit disposed in the feedback path;
- wherein a polarized state corresponding to the data held in the data holding circuit is memorized in the first ferroelectric capacitor by giving a writing signal to the other end of the first ferroelectric capacitor;
- and
- wherein the data corresponding to the polarized state memorized in the first ferroelectric capacitor is restored in the data holding circuit by giving a reading signal to the other end.
A data holding device comprising:
- a data storing circuit for releasing an amount of electric charge commensurate with stored data to an electric charge releasing node when a reading signal is given;
- a data restoring circuit for restoring contents of the data stored in the data storing circuit on the basis of a voltage produced at the electric charge releasing node with the released electric charge;
- and
- a field effect transistor having a drain region connected substantially to the electric charge releasing node and having a junction with its joining direction from the drain region to a base semiconductor region of the field effect transistor in agreement with a direction of the electric charge released;
- and
- wherein a voltage substantially the same as a source voltage that is to be given to a source region of the field effect transistor is started to be given to the base semiconductor region either simultaneously with or before giving the reading signal;
- and the source voltage is given to the source region after giving the reading signal.
A data holding device having a data holding circuit made to be capable of holding data by interconnecting, in a series loop, an inverter circuit disposed in a main signal path and an inverter circuit disposed in a feedback path, comprising:
- a first on-off gate disposed between the output node of the inverter circuit disposed in the feedback path and the input node of the inverter circuit disposed in the main signal path, the first on-off gate being on-off-controlled to become on state when data is held and to become off state when data is passed, and
- a first ferroelectric capacitor having its one end connected to the output node of the inverter circuit disposed in the feedback path,
- wherein the first ferroelectric capacitor is adapted to memorize the polarized state corresponding to the data present in the data holding circuit on the basis of the potential at the other end relative to the potential at one end of the first ferroelectric capacitor, and
- wherein the data holding circuit is adapted to restore the data corresponding to the polarized state stored in the first ferroelectric capacitor into the data holding circuit by giving a reading signal to the other end.
A method for reading data, using a data holding device having a data storing circuit for releasing an amount of electric charge commensurate with stored data to an electric charge releasing node when a reading signal is given;
- a data restoring circuit for restoring contents of the data stored in the data storing circuit on the basis of a voltage produced at the electric charge releasing node with the released electric charge;
- and a field effect transistor having a drain region connected substantially to the electric charge releasing node and having a junction with its joining direction from the drain region to a base semiconductor region of the field effect transistor in agreement with a direction of the electric charge released;
- the method comprising:
- starting to give a voltage substantially the same as a source voltage that is to be given to a source region of the field effect transistor, to the base semiconductor region either simultaneously with or before giving a reading signal to the data storing circuit;
- and
- giving the source voltage to the source region after giving the reading signal, to the data storing circuit.
Dependencies are inferred from the claim text.