TWI471866B - Power saving external USB mass storage device (mass storage device) and its power saving method - Google Patents

Description

Power-saving external USB mass storage device (mass storage device) and power saving method thereof

The invention relates to an external USB mass storage device, in particular to an external USB large-capacity memory device capable of automatically sleeping to achieve a power saving effect.

The external USB mass storage device is used as a portable data, and is used in conjunction with an external host (such as a notebook type) that accesses the external USB mass storage device. The USB mass storage device has a USB interface (Universal Serial Bus), and the bus terminal is inserted into the external host, and the external host can output a host command to the external USB mass storage device, further The external USB mass storage device performs data access. Please refer to FIG. 6 , which is a functional block diagram of a conventional external USB mass storage device 60 , which includes a USB interface 60 , a USB controller 62 , and an interface unit . 63. An interface controller 64 and a memory unit 65. The USB controller 62 is electrically connected to the USB interface 61 and the interface unit 63, and is electrically connected to an external host 70 through the USB interface 61. The interface unit 63 is electrically connected to the interface controller 64, and the interface controller 64 is electrically connected to the memory unit 65.

The external host 70 outputs a host command. When the external USB mass storage device 60 receives the host command, the USB controller 62 processes the command included in the host command, if the host command includes an internal command. The device controller 64 causes the interface controller 64 to access the memory unit 65 through the interface unit 63; if the internal device command is not included in the host command, the USB controller 62 processes the host After the command, the host is directly replied to.

For example, the general host periodically checks the status of the external device, so a host command including a polling command is issued to detect that the external USB mass storage device 60 is in an accessible or unplugged state. The USB controller 62 receives the main command and determines that it is a polling command, and instead of the internal device command, directly responds to the external host 70, and the interface unit 63, the interface controller 64, and the memory unit 65 do not operate; The interface unit 63 is in an active state, and the interface controller 64 is in a wake up state, so as to be directly stored through the interface unit 63 and the interface controller 64 when receiving the internal device command at any time. This memory unit 65 is taken.

Since the general user uses the external USB mass storage device 60, the memory unit 65 is not frequently accessed through the host for a long time. After the host is plugged into the host, the access data path is set and the access is released. After the command, the device waits for the data access to be completed; that is, the external USB mass storage device 60 is plugged into the host to perform the actual data access operation time, and the above description shows that the external USB is currently available. The large-capacity memory device 60 keeps the USB controller, the interface unit 63, and the interface controller 64 in a standby state in response to an untimely operation of the host, and responds to the host command in a timely manner, so that power is still consumed for a long time. .

Although the USB 1.1, 2.0, and 3.0 USB controllers have been configured with a sleep command (Suspend), for the external USB mass storage device 60, the host controller only controls the USB controller 62 to go to sleep, and cannot further control the The interface unit 63 and the interface controller 64 enter a sleep mode to reduce power consumption, and the usage habit of the general external USB mass storage device 60 does consume power for a long time, so the external USB mass storage device needs to have some Improvement.

In view of the technical defects that the existing external USB mass storage device does not read the external host for a long time, the main purpose of the present invention is to provide a power-saving external USB large-capacity memory device and the province thereof. Electrical method.

The main technical means for achieving the above purpose is that the power-saving external USB mass storage device comprises: a USB interface, a USB controller, an interface unit, an interface controller and a memory unit, and the The USB controller has a built-in sleep judging program for estimating that the external host of the USB mass storage device connected to the USB is not going to access the memory unit for a long time, and the USB controller passes through the interface. The unit triggers the sleep mode of the interface controller, so that the interface controller and its memory unit enter a low power consumption (Power down) to achieve power saving effect.

The sleep determination program of the USB controller is configured to filter whether the host command includes an internal device command as a basis for estimating whether the external host will not perform data access operations on the memory unit for a long time, and therefore the USB controller is configured with an instruction counting unit. , determining that the consecutive N host commands do not contain an internal device command, that is, the host has not issued an internal device command such as data access to the interface controller and its memory unit for a period of time; that is, the USB controller can drive the interface The sleep mode of the controller causes the interface controller and its memory unit to enter low power consumption and achieve a sleep effect.

The sleep determination program of the USB controller may also be set for a time period, and a counter of the USB controller performs counting of the time period to confirm whether a host command including an internal device command is not received within a single time period; if yes On behalf of the host, the data access operation of the memory unit is not performed for a long time, and the USB controller drives the sleep mode of the interface controller, so that the interface controller and its memory unit enter low power consumption to achieve the sleep effect.

Moreover, the main technical means used by the present invention to achieve the above object is that the power saving method of the power-saving external USB mass storage device includes: receiving an external host command; estimating the memory of the external USB mass storage device The data of the unit will not be read for a long time, and the frequency of receiving the external host command containing the internal device command is judged; and when the frequency of the received external host command containing the internal device command is low, the USB is triggered. The interface controller of the mass storage device enters the sleep mode; when it is determined that the received external host command contains the internal device command at a high frequency, the process returns to the first step.

The above judgment determines the frequency of the external host command including the internal device command, and sets an N value to determine whether the received host command has accumulated consecutive N host commands without an internal device command, and includes an internal judgment as a judgment. The frequency of the external host command of the device command; when the received consecutive N host commands do not include the internal device command, the internal device command that the host controller has not issued the data access to the interface controller and its memory unit for a period of time And let the interface controller enter the sleep mode to achieve the sleep effect.

The above judgment determines that the frequency of the external host command including the internal device command is set for a time period, and if the host command containing the internal device command is not received within a single time period, the host will not perform data for the memory unit for a long time. The access action is performed, and the interface controller enters a sleep mode, so that the interface controller and the memory unit enter a low power consumption to achieve a sleep effect.

Referring to FIG. 1 , the power-saving external USB mass storage device 10 of the present invention can be HD, ODD, and non-volatile memory, and is plugged into an external host 20 and includes a USB interface 11 is a Universal Serial Bus and is plugged into the external host 20 to receive a host command from the external host 20; a USB controller 12 is electrically connected to the USB interface 11 The USB interface 11 is electrically connected to the external host 20, and a sleep determination program is built in. An interface unit 13 is electrically connected to the USB controller 12. The interface unit 13 can be ATA, SATA, ATAPI, or SCSI. And a memory bus or a memory card bus; an interface controller 14 and including a sleep mode; and a memory unit 15 electrically connected to the interface controller 14.

The sleep determination program is configured to trigger the sleep mode of the interface controller 14 by the USB controller 12 through the interface unit 13 when the external host 20 is not going to perform data access operation on the memory unit 15 for a long time. The interface controller 14 and its memory unit 15 are allowed to enter low power consumption, and the interface unit 13 can be further switched to an inactive state to achieve power saving effect.

The sleep determination program of the USB controller 12 is based on whether the filter host command includes an internal device command as a basis for estimating whether the external host 20 will not perform data access operations on the memory unit for a long time. In this embodiment, the USB controller The 12 series designing an instruction counting unit determines that the consecutive N host commands do not include an internal device command, that is, the host has not issued an internal device command such as data access to the interface controller 14 and its memory unit 15 for a period of time; The USB controller 12 can drive the sleep mode of the interface controller 14 to make the interface controller 14 and its memory unit 15 enter low power consumption, and further enable the interface unit 13 to enter an inactive state to achieve a sleep effect.

The present invention further provides another preferred embodiment, wherein the sleep determination program of the USB controller 12 is set for a time period, and a counter of the USB controller 12 performs counting of the time period to confirm whether it is within a single time period. The host command containing the internal device command is not received; if it is, the host will not perform the data access operation to the memory unit for a long time, and the USB controller 12 drives the sleep mode of the interface controller 14, so that the interface controller 14 The memory unit 15 enters a low power consumption, and the interface unit 13 can be further brought into an inactive state to achieve a sleep effect.

The USB controller of the power-saving external USB mass storage device of the present invention further has a wake-up program built therein to control the interface controller 14 and its memory unit 15 to enter a low power consumption, and receive an instruction including an internal device. The host command can still successfully react to this internal device command by the interface controller 14. Please refer to FIG. 3 , which is a flowchart of the wake-up procedure. The wake-up procedure is executed after the USB controller 12 determines that the external host command includes an internal device command, and includes the following steps: start S41; confirm whether the interface unit 13 is Active state S42; if not, further activate the interface unit 13 (S43); if yes, perform the next step; confirm whether the interface controller 14 and the memory unit 15 (S44) are in a dormant state; Then, the interface controller 14 and the memory unit 15 are awakened (S45) and the internal device command is transmitted to the interface controller 14 through the interface unit 13 (S46).

Thus, when the USB controller 12 controls the interface unit 13 to enter an inactive state, and the interface controller 14 and its memory unit 15 enter a low power consumption state, upon receiving a host command including an internal device command, The interface unit 13 is returned to the active state, and then the interface controller 14 and its memory unit 15 are awake, and the internal device command is transmitted to the interface controller 14 through the interface unit 13, and the internal controller command is reacted by the interface controller 14; In this way, the external host 20 can complete the access operation to the memory unit 15 that has been hibernated through the USB controller 12.

Please refer to FIG. 2 , which is a power saving method for a power-saving external USB mass storage device 10 of the present invention, which includes: receiving an external host command S11; estimating a memory unit of the external USB mass storage device 10 The data of 15 will not be read for a long time, and it is judged that the frequency S12 of the external host command containing the internal device command is received; and when the frequency of the internal device command included in the received external host command is low, the trigger is triggered. The sleep mode S13 of the interface controller 14 of the USB mass storage device 10 causes the interface controller 14 and its memory unit 15 to enter low power consumption; when it is determined that the received external host command contains a high frequency of internal device commands, then Going back to the first step S11.

Please refer to FIG. 4 again, which is a flowchart of a power saving method for the power-saving external USB mass storage device 10 of the present invention, which mainly receives the external host command including the internal device command in the above judgment. In the frequency step, an N value is set, and the detailed procedure is as follows: receiving an external host command S21; accumulating the number of host commands S22, and determining whether N host commands S23 have been reached, and if not yet, returning to the first step S21; if yes, Then, the next step is performed; determining whether there is a host command S24 containing the internal device command among the received N host commands, and if so, returning the count to zero S23 and returning to the first step S21; if not, entering the sleep mode S25 .

This embodiment mainly presets an N value, and determines whether the received host command has accumulated consecutive N host commands without an internal device command, and thereby determines the frequency of the external host command including the internal device command; when receiving When the consecutive N host commands are not included in the internal device command, the host controller 14 has not issued an internal device command such as data access to the interface controller 14 and its memory unit 15 for a period of time, and the interface controller 14 is put into sleep. The mode causes the interface controller 14 and its memory unit 15 to enter low power consumption to achieve a power saving effect.

Please refer to FIG. 5 again, which is a flowchart of another preferred embodiment of the power-saving external USB large-capacity memory power-saving method according to the present invention, which mainly receives the external host command including the internal device command in the above judgment. Setting a time period in the frequency step, the detailed flow is as follows: start timing S31; receive an external host command S32; determine whether the external host command includes an internal device command S33; if it is included, re-count S34 and return to the first step S31; If the internal device command is not included, the next step is performed; it is determined whether the time has elapsed for the time period S35, and if so, the sleep mode S36 is entered; otherwise, if the time period has not yet reached, the process returns to the receiving host command step S32.

As can be seen from an embodiment, the present embodiment presets a time period and determines, in a single time period, that the received host command includes an internal device command as a judgment to receive an external host command including an internal device command. If the host does not receive the host command including the internal device command, the host will not perform the data access operation for the memory unit for a long time, and the interface controller 14 enters the sleep mode, so that the interface controller 14 and its memory unit 15 Enter low power consumption to achieve power saving effect.

In summary, the sleep determination program built in the USB controller of the present invention can predict that the external host will not access the memory unit for a long time, and further automatically enter the interface controller and the memory unit to enter low power consumption. When the memory unit is to be accessed, the interface controller and the memory unit are awakened, so that the power saving effect can be achieved by long-term use.

10. . . External USB mass storage device

11. . . USB interface

12. . . USB controller

13. . . Interface unit

14. . . Interface controller

15. . . Memory unit

20. . . External host

60. . . USB mass storage device

61. . . USB interface

62. . . USB controller

63. . . Interface unit

64. . . Interface controller

65. . . Memory unit

70. . . External host

Figure 1 is a functional block diagram of the present invention.

2 is a flow chart of a power saving method of the present invention.

Figure 3 is a flow chart of the wake-up procedure of the present invention.

4 is a flow chart of a sleep program according to a preferred embodiment of the present invention.

FIG. 5 is a flow chart of a sleep program according to another preferred embodiment of the present invention.

Figure 6: Functional block diagram of a conventional external USB mass storage device.

10. . . USB mass storage device

11. . . USB interface

12. . . USB controller

13. . . Interface unit

14. . . Interface controller

15. . . Memory unit

20. . . External host

Claims (8)

A power-saving external USB mass storage device includes: a USB interface for plugging in an external host to receive a host command of an external host; and a USB controller including an instruction counting unit, and Electrically connecting with the USB interface and having a sleep determination program; an interface unit electrically connected to the USB controller; an interface controller including a sleep mode; and a memory unit coupled to the interface controller Electrical connection for storing data; the USB controller performs a sleep determination procedure, and determines that the continuous N host commands do not include an internal device command, triggers a sleep mode of the interface controller through the interface unit, and causes the interface controller and The memory unit enters low power consumption. The power-saving external USB mass storage device according to claim 1, wherein the USB controller includes a timer and presets a time period to time whether a time period is not received within a single time period. The host command of the device command; if so, the sleep mode of the interface controller is driven to cause the interface controller and its memory unit to enter low power consumption. The power-saving external USB mass storage device according to claim 1 or 2, wherein the USB controller enters the interface unit into an inactive state after the interface controller and the memory unit thereof enter low power consumption. . For example, in the power-saving external USB mass storage device described in claim 3, the USB controller further includes a wake-up program, and executes the wake-up procedure when receiving a host command including an internal device command. And the wake-up procedure includes the steps of: starting; confirming whether the interface unit is in an active state; if not, further activating the interface unit; if yes, performing the next step; confirming whether the interface controller and the memory unit are a sleep state; if so, waking up the interface controller and the memory unit and transmitting the interface controller through the interface unit. The power-saving external USB mass storage device according to claim 1 or 2, wherein the interface unit is ATA, SATA, ATAPI, SCSI, memory bus or memory card bus (memory) Card bus). The power-saving external USB mass storage device described in claim 4, wherein the interface unit is ATA, SATA, ATAPI, SCSI, memory bus or memory card bus (memory card bus) ). A power saving method for a power-saving external USB mass storage device, wherein the external USB mass storage device comprises a USB interface, a USB controller, an interface unit, an interface controller and a memory unit; The power saving method includes: setting a value N; receiving an external host command; accumulating the number of host commands; and triggering the USB large when determining that the received external host command has accumulated consecutive N external host commands without an internal device command The interface controller of the capacity memory device enters the sleep mode, and the interface controller and its memory unit Entering low power consumption; and when determining that the received external host command at least one of the consecutive N external host commands includes an internal device command, returning to the step of receiving the external host command. The power saving method of the power-saving external USB mass storage device according to claim 7, wherein in the step of determining the frequency of receiving the external host command including the internal device command, setting a time period to a single During the time period, it is determined that the host command containing the internal device command is not received, and the interface controller enters the sleep mode, so that the interface controller and the memory unit enter low power consumption.