METHOD AND CIRCUIT FOR TRANSMITTING A MEMORY CLOCK SIGNAL

• US 20080052481A1
• Filed: 08/22/2006
• Published: 02/28/2008
• Est. Priority Date: 08/22/2006
• Status: Active Grant

• Current Assignee: Polaris Innovations Limited (Wi-LAN Inc.)
• Original Assignee: Qimonda AG (Infineon Technologies AG)
• Inventors: OH, JONG-HOON
• Granted Patent: US 7,886,122 B2
• Time in Patent Office: Days
• US Class Current: 711/167
• CPC Class Codes: G11C 2207/107 Serial-parallel conversion of data or prefetch
• CPC Class Codes: G11C 7/1051 Data output circuits, e.g. read-out amplifiers, data output buffers, data output registers, data output level conversion circuits
• CPC Class Codes: G11C 7/1069 I/O lines read out arrangements
• CPC Class Codes: G11C 7/1078 Data input circuits, e.g. write amplifiers, data input buffers, data input registers, data input level conversion circuits
• CPC Class Codes: G11C 7/22 Read-write [R-W] timing or clocking circuits; Read-write [R-W] control signal generators or management
• CPC Class Codes: G11C 7/225 Clock input buffers

Abstract

Embodiments of the invention generally provide a method and apparatus for transmitting and receiving clock signals. In one embodiment, the method includes receiving, at a memory device, a first clock signal and a second clock signal. The frequency of the first clock signal may be less than the frequency of the second clock signal. The method further includes performing two or more data access operations using the second clock signal. One of the two or more data access operations may include a read operation and one of the two or more data access operations may include a write operation. The method also includes performing a command processing operation using the first clock signal.

Claims

1. A method for transmitting clock signals, the method comprising:

receiving, at a memory device, a first clock signal and a second clock signal, wherein a frequency of the first clock signal is less than a frequency of the second clock signal;

performing two or more data access operations using the second clock signal, wherein at least one of the two or more data access operations includes a read operation and wherein at least one of the two or more data access operations includes a write operation; and

performing a command processing operation using the first clock signal.

2. The method of claim 1, further comprising:

performing a read operation with the second clock signal wherein separate read data are provided at rising and falling edges of a read clock signal generated from the second clock signal; and

performing a write operation with the second clock signal wherein separate write data are received at rising and falling edges of the second clock signal.

3. The method of claim 2, further comprising:

generating the read clock signal from the second clock signal, wherein the read clock signal has a frequency which matches the frequency of the first clock signal.

4. The method of claim 3, wherein the read clock signal is generated without a phase-locked loop circuit and wherein the read clock signal is generated without a delay-locked loop circuit.

5. The method of claim 1, wherein the frequency of the second clock signal is twice the frequency of the first clock signal.

6. The method of claim 1, wherein the memory device receiving the first clock signal and the second clock signal is a dynamic, random access memory (DRAM) memory device.

7. The method of claim 1, wherein the first clock signal and the second clock signal are received across a low-power, double-data rate (LP-DDR) interface.

8. The method of claim 1, further comprising:

receiving command data and address data for the command processing operation using the first clock signal.

9. A method for providing clock signals to a memory device, the method comprising:

providing, to the memory device, a first clock signal and a second clock signal, wherein a frequency of the first clock signal is less than a frequency of the second clock signal;

providing command data to the memory device using the first clock signal;

performing a read operation from the memory device using the second clock signal; and

performing a write operation to the memory device using the second clock signal.

10. The method of claim 9, wherein, while performing the read operation with the second clock signal, separate read data are read at rising and falling edges of a read clock signal generated from the second clock signal and wherein, while performing the write operation with the second clock signal, separate write data are written at rising and falling edges of the second clock signal.

11. The method of claim 10, wherein a frequency of the read clock signal matches the frequency of the second clock signal.

12. The method of claim 11, wherein the read clock signal is not generated from the second clock signal by a phase-locked loop circuit and wherein the read clock signal is not generated from the second clock signal by a delay-locked loop circuit.

13. The method of claim 9, wherein the frequency of the second clock signal is twice the frequency of the first clock signal.

14. The method of claim 9, wherein the memory device is a dynamic, random access memory (DRAM) memory device.

15. The method of claim 9, wherein the first clock signal and the second clock signal are provided across a low-power, double-data rate (LP-DDR) interface.

16. A memory device comprising:

a memory array;

an interface to a control device; and

circuitry configured to;

receive a first clock signal and a second clock signal via the interface, wherein a frequency of the first clock signal is less than a frequency of the second clock signal;

perform two or more data access operations using the second clock signal, wherein at least one of the two or more data access operations includes a read operation wherein data is read from the memory array and wherein at least one of the two or more data access operations includes a write operation where data is written to the memory array; and

perform a command processing operation using the first clock signal.

17. The memory device of claim 16, wherein the circuitry is further configured to:

perform a read operation with the second clock signal wherein separate read data are provided at rising and falling edges of a read clock signal generated from the second clock signal; and

perform a write operation with the second clock signal wherein separate write data are received at rising and falling edges of the second clock signal.

18. The memory device of claim 17, wherein the circuitry is further configured to:

generate the read clock signal from the second clock signal, wherein the read clock signal has a frequency which matches the frequency of the first clock signal.

19. The memory device of claim 18, wherein the read clock signal is generated without a phase-locked loop circuit and wherein the read clock signal is generated without a delay-locked loop circuit.

20. A device comprising:

an interface to a memory device; and

circuitry configured to;

provide, to the memory device, a first clock signal and a second clock signal via the interface, wherein a frequency of the first clock signal is less than a frequency of the second clock signal;

provide command data to the memory device using the first clock signal;

perform a read operation from the memory device using the second clock signal; and

perform a write operation to the memory device using the second clock signal.

21. The device of claim 20, wherein, while performing the read operation with the second clock signal, separate read data are read at rising and falling edges of a read clock signal generated from the second clock signal and wherein, while performing the write operation with the second clock signal, separate write data are written at rising and falling edges of the second clock signal.

22. The device of claim 21, wherein a frequency of the read clock signal matches the frequency of the second clock signal.

23. The device of claim 22, wherein the read clock signal is not generated from the second clock signal by a phase-locked loop circuit and wherein the read clock signal is not generated from the second clock signal by a delay-locked loop circuit.

24. A memory device comprising:

means for storing data;

means for interfacing a control device; and

circuitry configured to;

receive a first clock signal and a second clock signal via the means for interfacing, wherein a frequency of the first clock signal is less than a frequency of the second clock signal;

perform two or more data access operations using the second clock signal, wherein at least one of the two or more data access operations includes a read operation wherein data is read from the means for storing data and wherein at least one of the two or more data access operations includes a write operation where data is written to the means for storing data; and

perform a command processing operation using the first clock signal.

25. The memory device of claim 24, wherein the circuitry is further configured to:

perform a read operation with the second clock signal wherein separate read data are provided at rising and falling edges of a read clock signal generated from the second clock signal; and

perform a write operation with the second clock signal wherein separate write data are received at rising and falling edges of the second clock signal.

26. The memory device of claim 25, wherein the circuitry is further configured to:

generate the read clock signal from the second clock signal, wherein the read clock signal has a frequency which matches the frequency of the first clock signal.

27. The memory device of claim 26, wherein the read clock signal is generated without a phase-locked loop circuit and wherein the read clock signal is generated without a delay-locked loop circuit.

28. A system comprising:

a memory device; and

a control device configured to;

provide, to the memory device, a first clock signal and a second clock signal via the interface, wherein a frequency of the first clock signal is less than a frequency of the second clock signal;

provide command data to the memory device using the first clock signal;

perform a read operation from the memory device using the second clock signal, wherein the memory device is configured to process a read command for the read operation using the first clock signal and to provide a read clock signal generated from the second clock signal to the control device during transmission of read data for the read operation; and

perform a write operation to the memory device using the second clock signal, wherein the memory device is configured to process a write command for the write operation using the first clock signal.