Method for generating read enable signal and memory system using the method
A method for generating a read enable signal which is for controlling reading of a pair of data strobe signals and a data signal in a memory system is provided. The method comprises: detecting whether the pair of data strobe signals are both high or low; and generating the read enable signal if the pair of data strobe signals are detected being both high or low. Because the read enable signal is generated using the pair of strobe signals, DLL can be turned off, thus the power consumption of the memory system can be reduced. In addition, the read enable signal is self-aligned with a certain point of the pair of strobe signals, this may enhance precision of the transmission of the pair of strobe signals and the data signal.
1. A method for generating a read enable signal which is for controlling reading of a pair of data strobe signals and a data signal in a memory system, the method comprising:
detecting whether the pair of data strobe signals are both high or low; and
generating the read enable signal if the pair of data strobe signals are detected being both high or low, where the read enable signal is for controlling the reading of the pair of data strobe signals.
2. The method of claim 1 further comprising:
generating a trigger signal if the pair of data strobe signals are detected being both high or low, in the method, the read enable signal is generated after the trigger signal is detected.
3. The method of claim 1 the method further comprising:
generating the pair of data strobe signals, wherein the pair of data strobe signals comprise a segment in which the pair of data strobe signals are both high or low.
4. The method of claim 3 , wherein the pair of data strobe signals comprises a trigger segment, a pre-amble segment, and a strobe segment in order of time, in the trigger segment, the pair of data strobe signals are both high or low, in the pre-amble segment and the strobe segment, the pair of data strobe signals are differential signals.
5. The method of claim 1 , wherein the pair of data strobe signals and the data signal are generated by a memory chip, the read enable signal is generated by a data exchanging device which exchanges data directly with the memory chip.
6. The method of claim 5 , wherein the data exchanging device is a buffer which is mounted on the same memory module with the memory chip.
7. The method of claim 5 , wherein the data exchanging device is a memory controller for controlling reading data from and writing data to the memory chip.
8. A data exchanging device for reading in a pair of data strobe signals and a data signal from a memory chip, the data exchanging device comprising:
an enable signal generator for generating a read enable signal if the pair of data strobe signals are detected being both high or low;
a strobe signal receiver, connected with the enable signal generator, for reading in the pair of data strobe signals if it receives the read enable signal; and
a data signal receiver, connected with the enable signal generator, for reading in the data signal if it receives the read enable signal.
9. The data exchanging device of claim 8 , wherein the data exchanging device is a buffer mounted on the same memory module with the memory chip.
10. The data exchanging device of claim 8 , wherein the data exchanging device is a memory controller for controlling reading data from and writing data to the memory chip.
11. The data exchanging device of claim 8 further comprising a strobe signal detector connected with the enable signal generator, for generating a trigger signal if the pair of data strobe signals are detected being both high or low, in the data exchanging device, the enable signal generator generates the read enable signal after it receives the trigger signal.