Multi-port memory device

1. A multi-port memory device, comprising:

a global data bus;

a plurality of transmitters and receivers;

a termination means for controlling the global data bus to transmit the data in a range of a first voltage to a second voltage in response to an active mode signal; and

a voltage generator for generating the first and the second voltages,

wherein the first voltage is higher than a ground voltage and the second voltage is lower than a power supply voltage.

2. The multi-port memory device as recited in claim 1 , wherein the termination means includes:

a first NMOS transistor having a gate and a first terminal, the first terminal is connected to a power supply voltage terminal for receiving a third voltage through its gate, the third voltage obtained by adding a threshold voltage of the first NMOS transistor to the first voltage;

a first PMOS transistor having a gate, connected between a second terminal of the first NMOS transistor and the global data bus, for receiving an inverted active mode signal through its gate;

a second PMOS transistor having a gate and a first terminal, the second PMOS transistor's first terminal is connected to a ground voltage terminal for receiving a fourth voltage through its gate, the fourth voltage obtained by subtracting an absolute value of a threshold voltage of the second PMOS transistor from the second voltage; and

a second NMOS transistor having a gate, connected between a second terminal of the second PMOS transistor and the global data bus, for receiving the active mode signal through its gate.

3. The multi-port memory device as recited in claim 2 , wherein the voltage generator includes:

a reference voltage generator for generating a constant reference voltage based on the power supply voltage; and

a level shifter for receiving the constant reference voltage to generate the first and the second voltages.

4. The multi-port memory device as recited in claim 3 , wherein the level shifter includes:

a sink NMOS transistor having a gate, connected to the ground voltage terminal, for receiving a bias voltage through its gate;

a first input NMOS transistor having a gate, connected between the sink NMOS transistor and a first node, for receiving the constant reference voltage through its gate;

a second input NMOS transistor having a gate, connected between the sink NMOS transistor and a second node, for receiving a feedback reference voltage through its gate;

a first load PMOS transistor, connected between the first node and the power supply voltage terminal, for receiving a voltage loaded at the second node;

a second load PMOS transistor, connected between the second node and the power supply voltage terminal, for receiving the voltage loaded at the second node;

a drive PMOS transistor, connected between the power supply voltage terminal and a third node, for receiving a voltage loaded at the first node; and

a voltage divider, connected between the third node and the ground voltage terminal, for providing the feedback reference voltage,

wherein the first and the second load PMOS transistors form a current mirror and the third and the fourth voltages are outputted through the third node and an output terminal of the voltage divider, respectively.

5. The multi-port memory device as recited in claim 3 , wherein the reference voltage generator is one of a widlar generator and a band-gap generator.

6. The multi-port memory device as recited in claim 2 , wherein each of the transmitters includes a third and a fourth NMOS transistors serially connected to each other between the global data bus and the ground voltage terminal, the third and the fourth NMOS transistors respectively receiving a drive pulse and the data through their gates.

7. The multi-port memory device as recited in claim 6 , wherein each of the receivers is a current sensing receiver and includes:

a third PMOS transistor whose first terminal is connected to the power supply voltage terminal and second terminal and gate are diode-connected to each other;

a fourth PMOS transistor whose first terminal is connected to the power supply voltage terminal and second terminal is connected to an output terminal;

a fifth NMOS transistor having a first terminal connected to the second terminal of the third PMOS transistor, a second terminal connected to the global data bus, and a gate receiving a reference voltage;

a sixth NMOS transistor having a gate and a first terminal, the first terminal is connected to the output terminal and its gate receives the reference voltage; and

a seventh NMOS transistor having a first terminal connected to a second terminal of the sixth NMOS transistor, a second terminal connected to the ground voltage terminal, and a gate receiving an evaluation signal.

8. The multi-port memory device as recited in claim 1 , wherein the termination means includes:

a first PMOS transistor whose first terminal is connected to a power supply voltage terminal for receiving an inverted active mode signal;

a first NMOS transistor having a gate, connected between a second terminal of the first PMOS transistor and the global data bus, for receiving a third voltage through its gate, the third voltage obtained by adding a threshold voltage of the first NMOS transistor to the first voltage;

a second NMOS transistor having a gate and a first terminal, the first terminal is connected to a ground voltage terminal for receiving the active mode signal through its gate; and

a second PMOS transistor having a gate, connected between a second terminal of the second NMOS transistor and the global data bus, for receiving a fourth voltage through its gate, the fourth voltage obtained by subtracting an absolute value of a threshold voltage of the second PMOS transistor from the second voltage.

9. The multi-port memory device recited in claim 1 , wherein the transmitters and receivers each operate to exchange data with the global data bus.

10. A multi-port memory device, comprising:

a global data bus;

a plurality of transmitters and receivers;

a termination means for controlling the global data bus to transmit data in a range of a ground voltage to a first voltage, which is lower than a power supply voltage, in response to an active mode signal; and

a voltage generator for generating the first voltage.

11. The multi-port memory device as recited in claim 10 , wherein the termination means includes:

a first PMOS transistor having a gate and a first terminal, the first terminal is connected to a ground voltage terminal for receiving a second voltage through its gate; and

a first NMOS transistor having a gate, connected between a second terminal of the first PMOS transistor and the global data bus, for receiving the active mode signal through its gate,

wherein the second voltage is obtained by subtracting an absolute value of a threshold voltage of the first PMOS transistor from the first voltage.

12. The multi-port memory device as recited in claim 11 , wherein the voltage generator includes:

a reference voltage generator for generating a constant reference voltage based on the power supply voltage; and

a level shifter for generating the first voltage based on the constant reference voltage.

13. The multi-port memory device as recited in claim 12 , wherein the level shifter includes:

a sink NMOS transistor having a gate, connected to the ground voltage terminal, for receiving a bias voltage through its gate;

a first input NMOS transistor having a gate, connected between the sink NMOS transistor and a first node, for receiving the constant reference voltage through its gate;

a second input NMOS transistor having a gate, connected between the sink NMOS transistor and a second node, for receiving a feedback reference voltage through its gate;

a first load PMOS transistor, connected between the first node and a power supply voltage terminal, for receiving a voltage loaded at the second node;

a second load PMOS transistor, connected between the second node and the power supply voltage terminal, for receiving the voltage loaded at the second node;

a drive PMOS transistor, connected between the power supply voltage terminal and a third node, for receiving a voltage loaded at the first node; and

a voltage divider, connected between the third node and the ground voltage terminal, for providing the feedback reference voltage,

wherein the first and the second load PMOS transistors form a current mirror and the first voltage is outputted through an output terminal of the voltage divider.

14. The multi-port memory device as recited in claim 12 , wherein the reference voltage generator is provided with one of a widlar generator and a band-gap generator.

15. The multi-port memory device as recited in claim 11 , wherein each of the transmitters includes a second and a third NMOS transistor serially connected to each other between the global data bus and the ground voltage terminal, the second and the third NMOS transistors respectively receiving a drive pulse and data through their gates.

16. The multi-port memory device as recited in claim 15 , wherein each of the receivers includes:

a second PMOS transistor whose first terminal is connected to a power supply voltage terminal and second terminal and gate are diode-connected to each other;

a third PMOS transistor whose first terminal is connected to the power supply voltage terminal and second terminal is connected to an output terminal;

a fourth NMOS transistor having a first terminal connected to the second terminal of the second PMOS transistor, a second terminal connected to the global data bus, and a gate receiving a reference voltage;

a fifth NMOS transistor whose first terminal is connected to the output terminal and gate receives the reference voltage; and

a sixth NMOS transistor having a first terminal connected to a second terminal of the fifth NMOS transistor, a second terminal connected to the ground voltage terminal, and a gate receiving an evaluation signal.

17. The multi-port memory device as recited in claim 10 , wherein the termination means includes:

a first NMOS transistor having a gate and a first terminal, the first terminal is connected to the ground voltage terminal for receiving the active mode signal through its gate; and

a first PMOS transistor having a gate, connected between a second terminal of the first NMOS transistor and the global data bus, for receiving a second voltage through its gate,

wherein the second voltage is obtained by subtracting an absolute value of a threshold voltage of the first PMOS transistor from the first voltage.

18. The multi-port memory device as recited in claim 10 , wherein the plurality of transmitters are each current sensing transmitters and the plurality of receivers are each current sensing receivers, and the plurality of transmitters and the plurality of receivers each operate to exchange data with the global data bus.

19. A multi-port memory device, comprising:

a global data bus;

a plurality of transmitters and receivers;

a termination means for controlling the global data bus to transmit the data in a range of a power supply voltage to a first voltage, which is higher than a ground voltage, in response to an active mode signal; and

a voltage generator for generating the first voltage.

20. The multi-port memory device as recited in claim 19 , wherein the termination means includes:

a first NMOS transistor having a gate and a first terminal, the first terminal is connected to a power supply voltage terminal for receiving a second voltage through its gate; and

a first PMOS transistor having a gate, connected between a second terminal of the first NMOS transistor and the global data bus, for receiving an inverted active mode signal through its gate,

wherein the second voltage is obtained by adding a threshold voltage of the first NMOS transistor to the first voltage.

21. The multi-port memory device as recited in claim 19 , wherein the termination means includes:

a first PMOS transistor having a gate and a first terminal, the first terminal is connected to a power supply voltage terminal for receiving an inverted active mode signal through its gate; and

a first NMOS transistor having a gate, connected between a second terminal of the first PMOS transistor and the global data bus, for receiving a second voltage through its gate,

wherein the second voltage is obtained by adding a threshold voltage of the first NMOS transistor to the first voltage.

22. The multi-port memory device as recited in claim 20 , wherein the voltage generator includes:

a reference voltage generator for generating a constant reference voltage based on the power supply voltage; and

a level shifter for generating the first voltage based on the constant reference voltage.

23. The multi-port memory device as recited in claim 19 , wherein the plurality of transmitters are each current sensing transmitters and the plurality of receivers are each current sensing receivers, and the plurality of transmitters and the plurality of receivers each operate to exchange data with the global data bus.