Control method of memory system and related memory device

[Technical field]

The invention relates to a control method, and more particularly, relates to and is used for compensating the self-storage device transmitting the data strobe signal (data strobe signal, [...] DQS) offset (shift) of the storage system control method and related storage system, wherein the offset voltage from the voltage/temperature change induced.

[Background technology]

In general, when the storage system occurs in voltage or when the temperature is changed, the self-storage of sending of the DQS offset is induced. In response to the read command DQS for locking data. If the offset of the data strobe signal, the storage system can not read from the storage device the correct data. Thus, how to minimize the data strobe signal by the offset of the impact of the reading operation of the storage system is an important issue.

[The content of the invention]

In view of this, the threshing the following technical scheme:

The embodiment of the invention provides a storage system control method, comprising: after the condition is satisfied, the implementation of the retry operation, until the storage system enters the normal mode of operation; wherein the retry operation comprises: define a predetermined gating window, wherein predetermined gating window has an initial starting time point; by sending at least one 1st the read instruction to the storage device to the storage system of the storage device to carry out 1st virtual read operation, and in response to the at least one 1st the read instruction through the storage device to generate the data strobe signal; having an initial starting point of time of the decision of the gating window of the data strobe signal in a plurality of pulses is equal to the predetermined number of whether the number of 1st; and when the initial starting point of time of the decision of the gating window of the data strobe signal in a plurality of pulses is not equal to the number of 1st predetermined amount, through the gate window start time from the initial starting point of time to move to the 1st offset of the starting point of time to offset the gating window.

The embodiment of the invention also provides a storage system, comprising a storage device; and a memory controller, is coupled to the storage device, is used to control the memory device, wherein after the condition is satisfied, the storage controller performs the retry operation, in order to compensate sent from the storage device to the data strobe signal offset until the storage system enters the normal mode of operation.

Or more memory system control method and related storage device self-storage device correct reading of data.

[Attached drawing Figure]

Figure 1 is an example of the storage system of the embodiment.

Figure 2 is the schematic view of storage system different mode.

Figure 3A - 3B is the locking signal and the data strobe signal in the schematic view of the under different environmental temperature.

Figure 3C is the schematic view of the embodiment according to the exemplary due to ambient temperature variation data strobe signal offset and the locking signal gating window is the retry operation is offset.

Figure 4 is the schematic view of exemplary storage system according to the embodiment of different modes and mode switching.

Figure 5A - 5C show the memory system of the exemplary embodiment of the control method of the flow chart.

Figure 6 is the flow chart of exemplary embodiment the virtual read operation.

Figure 7A - 7C display control method of the memory system of another example of the embodiment of the flowchart.

[Embodiment]

In the specification and claims certain terms have been used in to refer to particular assembly. In the field of which belongs to the technical personnel should understand, manufacturers may use different terminology to refer to the same component. The specification and claims is not to name as a differentiation component of the difference of the way, but in order to assembly the functional differences in the distinction of as reference. In the entire specification and claims referred to in the book "comprising" are open terms, it should be translates "including but not limited to". In addition, the term "coupled" in this include any direct and indirect electrical connection means. Therefore, if the text described in the 2nd 1st device is coupled device, on behalf of the 1st device may be electrically connected directly to the 2nd device, or through other device or attachment means between the grounding electrical connected to the 2nd device.

Figure 1 is an example of the storage system of the embodiment. As shown in Figure 1, storage system 1 comprises a memory controller 10 and storage device 11. In this embodiment, storage device 11 is a dynamic random access memory (dynamic random access memory, [...] DRAM). The memory controller 10 and storage device 11 is arranged between the signal or data transmission. For example, the memory controller 10 to provide the clock signal CLK to the storage device 11 is in order to act on the data/signal receiving and transmitting of the basic clock. Sent from the memory controller 10 signal CMD/ADDR is used for notifying the storage device 10 a read or write operation to be executed in the storage device 10 on, and instructions will be access (read or write) data of the position. The data strobe signal DATA DQS and data in the memory controller 10 and storage device 11 between two-way transmission. For example, the read instruction through the signal CMD/ADDR is sent to the memory device 11 when, storage device 11 will during a read operation in response to the received read instruction is sent to the data strobe signal DATA DQS and corresponding data. For the write instruction, during a write operation to the data strobe signal DATA DQS and data transmission direction and during a read operation of the transmission in the opposite direction.

Storage system 1 operable in different modes, such as the normal mode of operation, the pause mode, frequency scaling (scaling) mode and the like. Operation in the normal mode, the storage system 1 implementation of the read and write data of normal operation. When the storage system 1 is operated in the pause mode, the frequency of operation ranging from a low of 0 Hz. At this time, the storage system 1 is in a self refresh state or the depth of the power-down state. When the storage system 1 is operated in the frequency scaling mode, storage system 1 the operating frequency of the initial frequency into a higher or lower frequency. That is, the storage system 1 is to adopt the dynamic voltage and frequency scaling (DVFS) used for power management technology of the storage system. In the subsequent paragraphs, provide the environment temperature change is used as the description of the example.

In the switch memory system 1 during the mode, storage system 1 of the environmental temperature or operating voltage may change. Ambient temperature or voltage of the operating voltage change may lead to important signal in the time line (time line) occurs on the offset, so that the storage system 1 is not the correct implementation of the read/write operation. For example, Figure 2 is the schematic view, as shown in Figure of storage system different mode 2 shown, first of all, when the environmental temperature is TEMP T1 (TEMP=T1) when, the storage system 1 is operated in the normal mode of operation (module 20). In the environmental temperature is TEMP T1 of the normal mode of operation (module 20) period, when the storage controller 10 through a signal CMD/ADDR transmits a read instruction to the memory device 11 is, the memory device 11 in response to the received read instruction DQS transmitting the data strobe signal to the memory controller 10. At this time, the memory controller 10 in response to a read strobe window (gate window) with the locking signal GW LATCH, as shown in Figure 3 A shown. Figure 3A - 3B is the locking signal and the data strobe signal in the schematic view of the under different environmental temperature. Figure 3C is the schematic view of the embodiment according to the exemplary due to ambient temperature variation data strobe signal offset and the locking signal gating window is the retry operation is offset. The gating window GW has a fixed time period. Gating windows in the GW DQS data strobe signal pulse used for the self-storage device 11 locking data DATA. The gating window STP30 GW has a starting time point. The starting time point STP30 in the read instruction is sent to the memory device 11 after. In other words, in the read instruction read delay (depends on the storage system 1 response time) after, the initial time point STP30 occurred. For example, according to the stored system 1 design and demand, STP30 starting time point after, data strobe signal DQS four pulse, includes four pieces of the rising edge and the four falling edge. When the data strobe signal DQS of all four pulse used for each of a read instruction occurs in GW gating window, corresponding to the success of the read operation.

Subsequently, the storage system 1 is switched to the operate mode to suspend mode or frequency scaling (module 21). In pause mode or frequency scaling mode, ambient temperature TEMP self-T1 change is T2 (TEMP=T1 ->T2). In the storage system 1 by the suspend mode or frequency scaling mode (module 21) switching back to the normal operating mode of operation (module 22) after, the environment temperature may still be TEMP for T2. In the environmental temperature T2 of the normal mode of operation (module 22) period, when the storage controller 10 through a signal CMD/ADDR transmits a read instruction to the memory device 11 is, the memory device 11 in response to the received read instruction sending data strobe signal DQS to the memory controller 10. In this example, due to environmental temperature TEMP change, in response to a read instruction is sent from the storage device 11 to the data strobe signal is offset by a DQS. As shown in Figure 3 B shown, the data strobe signal on a time axis DQS offset to the right. However, the locking signal LATCH gating window GW is not shorten or lengthen. Thus, the storage controller 11 can not be locked in the GW gating window of the received data strobe signal DQS four pulse. In details, please reference view 3 B, in the Figure only three rising edge and the falling edge four, not with the storage system 1 consistent with the design and requirements. Accordingly, the memory controller 10 cannot perform its normal read operation from the memory device 11 correct reading of data.

. Therefore, the provision of the retry operation to compensation due to environmental temperature/voltage of the operating voltage changes the data strobe signal DQS induced offset. Please reference view 4, Figure 4 is the schematic view of exemplary storage system according to the embodiment of different modes and mode switching. In the storage system 11 to withdraw from the suspended mode or frequency scaling mode (module 21) after the storage system and enter into the normal mode of operation (module 22) before, the storage system 1 is in the retry mode (module 40), in order to carry out the compensation data strobe signal offset DQS retry operation. Figure 5A - 5C display on the retry operation control method of the flow chart of exemplary embodiment.

As shown in Figure 5A - 5C shown, when the condition is satisfied, the memory controller 10 starts to execute the retry operation (step S500). The memory controller 10 retry operation until the implementation of the storage system 1 to enter the normal mode of operation (module 22). In a particular embodiment, when the storage system 1 from the suspended mode (as shown in Figure 2 of the module 21) when, the condition is satisfied. Namely, the retry operation is the implementation of the storage system 11 to withdraw from the suspended mode (Figure 2 indicated by the module 21) and after storage system enters the normal mode of operation (Figure 2 indicated by the module 22) before. The storage system 1 is in the retry mode (module 40) in order to carry out the retry operation. In another embodiment, when the storage system 1 the frequency of operation of the current frequency to change to the different-frequency (storage system 1 from the frequency scaling mode) when, the condition is satisfied. Namely, the retry operation is carried out on the frequency scaling mode (Figure 2 indicated by the module 21) and after storage system enters the normal mode of operation (Figure 2 indicated by the module 22) before. The storage system 1 is in the retry mode (module 40) in order to carry out the retry operation.

In a retry operation, memory controller 10 has an initial starting time point definition STP30 predetermined gating window GW (step S501). In this embodiment, used for storage system 1 at the time of the normal operation (i.e. Figure 2 indicated by the module 20) read operation is performed in the GW of the gating window as a predetermined strobe window. Thus, the gating window start time point of the GW STP30 as an initial starting time point. Subsequently, the memory controller 10 to storage device 11 to the implementation of the virtual read operation R #1, and decided to virtual read operation R #1 whether or not (step S502) successful implementation. Figure 6 show steps S502 details, Figure 6 is the flow chart of exemplary embodiment the virtual read operation. Please reference view 6, in a virtual during a read operation, the memory controller 10 sends a reading instruction to the memory device 11 (step S60). Subsequently, memory controller 10 waiting from the storage means 11 of the response. When the storage control device 10 receives the memory device 11 in response to the read command and generating data strobe signal when the DQS, (step S61), the memory controller 10 locking signal LATCH decision of the current gating window (i.e. has an initial starting time point STP30 initial gating window) in the DQS data strobe signal of a plurality of pulses is equal to the predetermined number of 1st whether the number (step S62). The embodiment of the invention, 1st predetermined quantity is 4. The embodiment of the invention, through the decision of the current gating window DQS data strobe signal in the rising edge of the 2nd whether the number is equal to the predetermined number (in this embodiment, a predetermined number of 2nd to 4), and the decision of the current gating window in the data strobe signal of the falling edge of the DQS whether the number equal to the 3rd a predetermined number (in this embodiment, 3rd predetermined number is 4), memory controller 10 decides the locking signal LATCH current gating window of the data strobe signal in a plurality of pulses of the DQS whether the number is equal to 4. When the storage controller 10 decides the current gating window DQS data strobe signal in the rising edge of the not equal to the number of 4, or to determine the current gating window in the data strobe signal of the falling edge of the DQS not equal to the number of 4 time, memory controller 10 decides the current gating window DQS data strobe signal in a plurality of pulses is not equal to the number of 4.

When in step S502 in, storage controller 10 having an initial starting point of time of the decision of the current gating window DQS data strobe signal in a plurality of pulse number is not equal to 4 when, memory controller 10 decides the virtual read operation R #1 is not successful. Subsequently, memory controller 10 stores the system 1 is greater than the operating speed of the speed threshold (step S503). When the storage controller 10 stores the system 1 is larger than the operation speed of the speed threshold value, the memory controller 10 through the gate window of time from an initial starting point in time of the initial STP30 mobile to the offset of the starting point of time to deflect the locking signal LATCH gating window, wherein the offset of the starting point of time earlier than an initial starting time point STP30 occurred (step S504). The data strobe signal of the DQS a pulse time period is defined as an offset unit UI. In step S504 in, the mobile of the starting point of time and the initial starting point of time of the interval between the two offset unit UI (2 UI), namely, the initial time from an initial starting time point STP30 - 2UI offset, wherein the offset direction marked "-" "to the left".

Subsequently, the memory controller 10 to storage device 11 to the implementation of the virtual read operation R #2, and decided to virtual read operation R #2 (step S505) success. Step S505 of the detailed operation is similar to Figure 6 is shown the operation of S60 - S62. In step S505 in, for virtual read operation R #2 the locking signal LATCH of the current gating window is a starting point of time relative to the initial starting time point STP30 - 2UI is offset by the gating window. At step S505 in the, memory controller 10 decision - 2UI starting point of time offset of the current gating window DQS data strobe signal in a plurality of pulse equal to the number 4 when, memory controller 10 decides the virtual read operation R #2 successfully. The memory controller 10 through the gate window of a starting point of time to another offset of the starting point of time to deflect the locking signal LATCH gating window, the other of the offset of the starting point of time earlier than an initial starting time point STP30 occurred (step S506), and then the end of the retry operation. In step S506 in, the mobile of the starting point of time and the interval between the initial starting time point is 1.5 offset unit UI (1.5 UI), namely, the initial time from an initial starting time point STP30 offset - 1 . 5UI. Accordingly, offset - 1 . 5UI gating windows for the initial time point of an initial starting time point STP30 and offset - 2UI gating window between the initial time point. When the storage system 1 to enter the normal mode of operation (module 22), and in the normal mode of operation when the read operation is performed, the storage system 1 based on the start time point offset - 1 . 5UI gating window self-storage device 11 locking data. On the other hand, when in step S505 in the, memory controller 10 decision - 2UI starting point of time offset of the current gating window DQS data strobe signal in a plurality of pulse number is not equal to 4 when, memory controller 10 decides the virtual read operation R #2 is not successful. The memory controller 10 through the gate window of a starting point of time to another offset of the starting point of time to deflect the locking signal LATCH gating window, the other of the offset of the starting time point in an initial starting time point STP30 (step S507) that occur after the. In step S507 in, the mobile of the starting point of time and the interval between the initial starting time point is 2 offset unit UI (2 UI), namely, the initial time from an initial starting time point STP30 offset + 2 UI, wherein said offset direction "+" "to the right". Accordingly, an initial starting time point STP30 strobe window located offset + 2 UI starting point of time and of the gating window offset - 2UI between the initial time point.

Subsequently, the memory controller 10 to storage device 11 to the implementation of the virtual read operation R #3, and decided to virtual read operation R #3 (step S508) success. Step S508 of the detailed operation is similar to Figure 6 is shown the operation of S60 - S62. In step S508 in, for virtual read operation R #3 LATCH locking signal of the current gating window is a starting point of time is offset + 2 UI gating window. When in step S508 in, storage controller 10 decides a starting point of time offset + 2 UI of the current gating window DQS data strobe signal in a plurality of pulse equal to the number 4 when, memory controller 10 decides the virtual read operation R #3 successful. The memory controller 10 through the gate window of a starting point of time to another offset of the starting point of time to deflect the locking signal LATCH gating window, the other of the offset of the starting time point in an initial starting time point STP30 (step S509) occur after, and then the end of the retry operation. In step S509 in, the mobile of the starting point of time and the interval between the initial starting time point is 1.5 offset unit UI (1.5 UI), namely, the initial time from an initial starting time point STP30 offset + 1.5 UI. Accordingly, offset + 1.5 UI gating windows for the initial time point of an initial starting time point STP30 and offset + 2 UI gating window between the initial time point. When the storage system 1 to enter the normal mode of operation (module 22), and in the normal mode of operation when the read operation is performed, the storage system 1 based on the start time point offset + 1.5 UI gating window self-storage device 11 locking data. On the other hand, when in step S508 in, storage controller 10 decides a starting point of time offset + 2 UI of the current gating window DQS data strobe signal in a plurality of pulse number is not equal to 4 when, memory controller 10 decides the virtual read operation R #3 is not successful. Subsequently, memory controller 10 according to the storage system 1 design and demand decided whether the retry operation (step S510) will end. When the storage controller 10 will retry operation at the end of the decision, the memory controller 10 release interrupt to indicate to the data strobe signal DQS offset compensation is not successful (step S511) and the end of the retry operation.

When the storage controller 10 decision will not be at the end of the retry operation, the memory controller 10 through the gate window of a starting point of time to another offset of the starting point of time to deflect the locking signal LATCH gating window, the other of the offset of the starting point of time earlier than an initial starting time point STP30 occurred (step S512). In step S512 in, the mobile of the starting point of time and the interval between the initial starting time point is 1 offset unit UI (- 1UI), namely, the initial time from an initial starting time point STP30 - 1UI offset, as shown in Figure 3 C shown. Accordingly, offset - 1UI gating windows for the initial time point of an initial starting time point STP30 and offset - 2UI gating window between the initial time point.

The memory controller 10 to storage device 11 to the implementation of the virtual read operation R #4, and decided to virtual read operation R #4 (step S513) success. Step S513 of the detailed operation is similar to Figure 6 is shown the operation of S60 - S62. In step S513 in, for virtual read operation R #4 locking signal LATCH of the current gating window is a starting point of time is offset by the - 1UI gating window. When in step S513 in, storage controller 10 decision - 1UI starting point of time offset of the current gating window DQS data strobe signal in a plurality of pulse equal to the number 4 when, memory controller 10 decides the virtual read operation R #4 successful, as shown in Figure 3 C shown. The memory controller 10 subsequently kept a starting point of time offset - 1UI gating window (step S514), and then the end of the retry operation. When the storage system 1 to enter the normal mode of operation (module 22), and in the normal mode of operation when the read operation is performed, the storage system 1 based on the start time point offset - 1UI gating window self-storage device 11 locking data. On the other hand, when in step S513 in, storage controller 10 decision - 1UI starting point of time offset of the current gating window DQS data strobe signal in a plurality of pulse number is not equal to 4 when, memory controller 10 decides the virtual read operation R #4 failure. The memory controller 10 through the gate window of a starting point of time to another offset of the starting point of time to deflect the locking signal LATCH gating window, the other of the offset of the starting time point in an initial starting time point STP30 (step S515) that occur after the. In step S515 in, the mobile of the starting point of time and the interval between the initial starting time point is 1 offset unit UI (1 UI), namely, the initial time from an initial starting time point STP30 offset + 1 UI. Accordingly, an initial starting time point STP30 strobe window located offset + 1 UI starting point of time and of the gating window offset - 1UI between the initial time point.

Subsequently, the memory controller 10 to storage device 11 to the implementation of the virtual read operation R #5, and decided to virtual read operation R #5 (step S516) success. The step S516 of the detailed operation is similar to Figure 6 is shown the operation of S60 - S62. In step S516 in, for virtual read operation R #5 of the locking signal LATCH current gating window is a starting point of time is offset + 1 UI gating window. When in step S516 in, storage controller 10 decides a starting point of time offset + 1 UI of the current gating window DQS data strobe signal in a plurality of pulse equal to the number 4 when, memory controller 10 decides the virtual read operation R #5 successful. The memory controller 10 subsequently kept gating window offset + 1 UI of a starting point of time (step S517), and then the end of the retry operation. When the storage system 1 to enter the normal mode of operation (module 22), and in the normal mode of operation when the read operation is performed, the storage system 1 based on the start time point offset + 1 UI gating window self-storage device 11 locking data. However, when in step S516 in, storage controller 10 decides a starting point of time offset + 1 UI of the current gating window DQS data strobe signal in a plurality of pulse number is not equal to 4 when, memory controller 10 decides the virtual read operation R #5 is not successful. The memory controller 10 release interrupt to indicate to the data strobe signal DQS offset compensation is not successful (step S518) and the end of the retry operation.

When in step S503 in, storage controller 10 stores the system 1 is not greater than the operating speed of the speed threshold value, control method directly enter step S512. According to this embodiment, in step S502 the virtual read operation R #1 not successful cases, has a greater speed by the operation of the storage system 1 virtual read operation carried out by the total of the number of times more than the number with a smaller speed by operation of the storage system 1 of the virtual read operation carried out by the number of times of the total number of (5>3).

In the above-mentioned examples, the retry operation is terminated in step S506, S509, S514 and S517 one, means that the gating window through the offset to the data strobe signal DQS offset compensation is completed. Thus, the gating window DQS data strobe signal in four pulse, as shown in Figure 3 C shown. When the storage system 1 in the normal mode of operation (module 22) to carry out the read operation, the memory controller 10 can be based on an offset of the gating window strobe window correct self-storage device 11 read data.

When in step S502 in, storage controller 10 having an initial starting point of time of the decision of the current gating window DQS data strobe signal in a plurality of pulse equal to the number 4 when, memory controller 10 decides the virtual read operation R #1 success. Subsequently, memory controller 10 according to the storage system 1 the design and requirements of the decision of whether to conclude the retry operation (step S519). When the storage controller 10 will retry operation at the end of the decision, the memory controller 10 to maintain an initial starting time point STP30 (by + 0 UI expressed), and then the end of the retry operation (step S520). When the storage system 1 to enter the normal mode of operation (module 22), and in the normal mode of operation when the read operation is performed, the storage system 1 has an initial starting time point based on the STP30 gating window self-storage device 11 locking data. In one embodiment, when the storage system 1 requires more short wake-up time, the retry operation will be decided at step S519 end, that is, there is only one virtual read operation (virtual read operation R #3) is carried out.

When the storage controller 10 decision will not be at the end of the retry operation, the memory controller 10 through the gate window of a starting point of time to another offset of the starting point of time to deflect the locking signal LATCH gating window, the other of the offset of the starting point of time earlier than an initial starting time point STP30 occurred (step S521). In step S521 in, the mobile of the starting point of time and the interval between the initial starting time point is 1 offset unit UI (- 1UI), namely, the initial time from an initial starting time point STP30 offset - 1UI. As described above, the existence of the virtual read operation successful R #1, meant data strobe signal DQS offset less or no offset DQS data strobe signal. Thus, in this embodiment, because as a result of successful virtual read operation the occurrence of R #1, step S521 gating window in the offset of the starting point of time of less than step S504 in the initial time point of the gating window of the offset. In the retry operation will continue under the condition of, a starting point of time of the gating window offset less. In this embodiment, step S521 in the offset value (1 UI) less than step S504 in the offset value (2 UI) (1 UI<2 UI).

The memory controller 10 to storage device 11 to the implementation of the virtual read operation R #2 ', and decided to virtual read operation R #2' (step S522) success. Step S522 detailed operation similar to Figure 6 is shown the operation of S60 - S62. In step S522 in, for virtual read operation R #2' of the locking signal LATCH current gating window is a starting point of time is offset by the - 1UI gating window. When in step S522 in, storage controller 10 decision - 1UI starting point of time offset of the current gating window DQS data strobe signal in a plurality of pulse equal to the number 4 when, memory controller 10 decides the virtual read operation R #2' successful, as shown in Figure 3 C shown. The memory controller 10 through the gate window of a starting point of time to another offset of the starting point of time to deflect the locking signal LATCH gating window, the other of the offset of the starting point of time earlier than an initial starting time point STP30 occurred (step S523), and then the end of the retry operation. In step S523 in, the mobile of the starting point of time and the interval between the initial starting time point is 0.5 offset unit UI (0.5 UI), namely, the initial time from an initial starting time point STP30 offset - 0 . 5UI. Accordingly, offset - 0 . 5UI gating windows for the initial time point of an initial starting time point STP30 - 1UI and offset of the starting point of time between the strobe window. When the storage system 1 to enter the normal mode of operation (module 22), and in the normal mode of operation when the read operation is performed, the storage system 1 based on the start time point offset - 0 . 5UI gating window self-storage device 11 locking data. However, when in step S522 in, storage controller 10 decision - 1UI starting point of time offset of the current gating window DQS data strobe signal in a plurality of pulse number is not equal to 4 when, memory controller 10 decides the virtual read operation R #2' is not successful. The memory controller 10 through the gate window of a starting point of time to another offset of the starting point of time to deflect the locking signal LATCH gating window, the other of the offset of the starting time point in an initial starting time point STP30 (step S524) that occur after the. In step S524 in, the mobile of the starting point of time and the interval between the initial starting time point is 1 offset unit UI (1 UI), namely, the initial time from an initial starting time point STP30 offset + 1 UI. Accordingly, an initial starting time point STP30 strobe window located offset + 1 UI starting point of time and of the gating window offset - 1UI between the initial time point.

Subsequently, the memory controller 10 to storage device 11 to the implementation of the virtual read operation R #3 ', and decided to virtual read operation R #3' (step S525) success. Step S525 detailed operation similar to Figure 6 is shown the operation of S60 - S62. In step S525 in, for virtual read operation R #3' of the locking signal LATCH current gating window is a starting point of time is offset + 1 UI gating window. When in step S525 in, storage controller 10 decides a starting point of time offset + 1 UI of the current gating window DQS data strobe signal in a plurality of pulse equal to the number 4 when, memory controller 10 decides the virtual read operation R #3' success. The memory controller 10 through the gate window of a starting point of time to another offset of the starting point of time to deflect the locking signal LATCH gating window, the other of the offset of the starting time point in an initial starting time point STP30 (step S526) occur after, and then the end of the retry operation. In step S526 in, the mobile of the starting point of time and the interval between the initial starting time point is 0.5 offset unit UI (0.5 UI), namely, the initial time from an initial starting time point STP30 offset + 0.5 UI. Accordingly, offset + 0.5 UI gating windows for the initial time point of an initial starting time point STP30 and offset + 1 UI gating window between the initial time point. When the storage system 1 to enter the normal mode of operation (module 22), and in the normal mode of operation when the read operation is performed, the storage system 1 based on the start time point offset + 0.5 UI gating window self-storage device 11 locking data. On the other hand, when in step S525 in, storage controller 10 decides a starting point of time offset + 1 UI of the current gating window DQS data strobe signal in a plurality of pulse number is not equal to 4 when, memory controller 10 decides the virtual read operation R #3' is not successful. Subsequently, memory controller 10 through the gate window moves to the initial time point of an initial starting time point STP30 offset locking signal LATCH gating window (by + 0 UI expressed) (step S527), and then the end of the retry operation. When the storage system 1 to enter the normal mode of operation (module 22), and in the normal mode of operation when the read operation is performed, the storage system 1 has an initial starting time point based on the STP30 gating window self-storage device 11 locking data.

As mentioned above, at step S502, the memory controller 10 decides the virtual read operation R #1 successfully, control method go to step S519. Thus, the subsequent step S521 - 527 carried out to fine offset the gating window, in order to ensure that any one of the normal mode of operation during a read operation the memory device 11 of the data can be more correctly read.

In one embodiment, steps S503 and are not included in the control method. Figure 7A - 7C display control method of the memory system of another example of the embodiment of the flowchart. In step S502 after, control method directly go to step S504 to the gate window of a starting point of time offset - 2UI, as shown in Figure 7 B shown. In this case, the decision of whether or not the retry operation towards the end of the is based on the storage system 1 of the operation speed. When the storage controller 10 stores the system 1 is not greater than the operating speed of the speed threshold value, the memory controller 10 decides the retry operation will end. Subsequently, the control method proceeds to step S511, and the end of the retry operation. When the storage controller 10 stores the system 1 is larger than the operation speed of the speed threshold value, the memory controller 10 decides the retry operation will not end. Subsequently, the control method proceeds to step S512, and the implementation of the subsequent virtual read operation. Figure 7A - 7C in other steps similar to Figure 5A - 5C in step of, for the sake of brevity, not repeat.

In one embodiment, storage system 1 to carry out the control method of the step S504, S506, S507 and S509 in the offset of the starting point of time according to the environmental temperature or operating voltage change of the tolerance (tolerance) decision. With relatively high ambient temperature or operating voltage change tolerance of the storage system 1 to carry out the control method of the step S504, S506, S507 and S509 in the offset is greater than the initial time point with a relatively low temperature environment or operating voltage change tolerance of the storage system 1 to carry out the control method of the step S504, S506, S507 and S509 in the starting time point of the offset. For example, in fig. 2 in the embodiment of the, the environmental temperature change is the maximum tolerance of 100 °C storage system, step S504, S506, S507 and S509 in the offset value for the initial time point are - 2UI, - 1 . 5UI, + 2 UI and + 1.5 UI. In another embodiment, the environmental temperature change is the maximum tolerance 70 °C storage system, step S504, S506, S507 and S509 in the starting time point of the offset value is - 1 . 5UI respectively, - 1UI, + 1.5 UI and + 1 UI.

The specification discloses the invention of preferred embodiments and examples, but it should be understood, the invention is not limited to the disclosed embodiment. On the contrary, the disclosed embodiment of the described above can make the skilled in the art can realize or use the invention. For for technical personnel in the field, these embodiment and it is obvious that various changes, and here defined overall principle can also be in the does not break away from the scope of the invention and the substance of the basis to the other embodiments. Therefore, the invention is not limited to the embodiment here shown, but here with the consistent with the disclosed principles and novel feature consistent with the most wide range.