Electronic flash memory external storage method and device

• US 7,788,447 B2
• Filed: 07/24/2004
• Issued: 08/31/2010
• Est. Priority Date: 11/14/1999
• Status: Expired due to Term

• Current Assignee: Netac Technology Company Limited
• Original Assignee: Netac Technology Company Limited
• Inventors: Cheng, Xiaohua, Deng, Guoshun
• Primary Examiner(s): Thai; Tuan V
• Assistant Examiner(s): Li; Zhuo H
• Application Number:
  US10/897,519
• Publication Number:
  US 20050036396A1
• Time in Patent Office: 2,229 Days
• Field of Search: 711102-103, 711/4, 711/100, 711113-115, 713 1- 2, 713/100, 365/189.011, 365/189.02, 365/189.15, 365/189.16, 365/189.17, 365/191, 365/193, 365/194, 365/226, 365/230.01, 365/230.02, 710/100, 710301-302, 710/105, 710313-315
• US Class Current: 711/115
• CPC Class Codes: G06F 12/1433 for a module or a part of a module
• CPC Class Codes: G06F 2206/1014 One time programmable [OTP] memory, e.g. PROM, WORM
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0626 Reducing size or complexity of storage systems
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• CPC Class Codes: G06F 3/0655 Vertical data movement, i.e. input-output transfer; data movement between one or more hosts and one or more storage devices
• CPC Class Codes: G06F 3/0658 Controller construction arrangements
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

An electronic flash memory external storage method and device for data processing system, includes firmware which directly controls the access of electronic storage media and implements standard interface functions, adopts particular reading and writing formats of the external storage media, receives power via USB, externally stores date by flash memory and access control circuit 2 with the cooperation of the firmware, driver and operating system, and has write-protection so that the data can be safely transferred. The method according to present invention is highly efficient and all parts involved are assembled as a monolithic piece so that it has large-capacity with small size and high speed. The device operates in statistic state and is driven by software. It is plug-and-play and adapted to data processing system.

Claims

1. A portable flash memory storage device comprising:

at least one flash memory module built-in said device, wherein said flash memory module is arranged on a block basis;

a USB or IEEE 1394 connector for establishing a data exchange channel between a host computer and said flash memory module based on USB or IEEE 1394 standard;

a microprocessor for processing commands to directly access data or information in the said flash memory module, said microprocessor further comprises a firmware for processing user requests to access the flash memory module; and

a circuit connected with said USB or IEEE 1394 connector and said flash memory module, through which a DC power supply is provided from said host computer through said USB or IEEE 1394 connector to said flash memory module and said microprocessor upon connecting said portable flash memory storage device with said host computer,

wherein said portable flash memory storage device only acquires DC power from the host computer through said USB or IEEE 1394 connector; and

wherein said microprocessor coordinates with a driver for the portable flash memory device in the host computer to assign and display a device symbol for said portable flash memory device upon connecting said USB or IEEE 1394 connector to the host computer.

2. A portable flash memory storage device according to claim 1, further comprises a suspend/resume circuit, connected with said flash memory module, for reducing the consumption of DC power supply from the host computer through said USB or IEEE 1394 connector.

3. A portable flash memory storage device according to claim 2, wherein said suspend/resume circuit further comprises a switching circuit for automatically changing between a suspend operation and a resume operation.

4. A portable flash memory storage device according to claim 1, further comprising a write protection circuit, connected with said flash memory module, for protecting against unwanted write operation.

5. A portable flash memory storage device according to claim 4, wherein said write protection circuit further comprises a toggle switch, connected to a write protection pin of the flash memory module, for changing a status of the write protection pin of said flash memory module.

6. A portable flash memory storage device according to claim 1, wherein said circuit further comprises an output pin which is connected with a power supply pin of said flash memory module.

7. A portable flash memory storage device according to claim 1, wherein said microprocessor further comprises an operating system for initialization, processing, and notification operations.

8. The portable flash memory storage device according to claim 1, wherein the driver is capable of converting a request in magnetic disk format into a special operation instruction for the device.

9. The portable flash memory storage device according to claim 1, wherein the firmware and the driver together provide a software write protection for the device.

10. The portable flash memory storage device according to claim 1 which is capable of plug-and-play.

11. The portable flash memory storage device according to claim 1, wherein said firmware performs read, write or erase operations on the flash memory module on a block basis in response to a user'"'"'s request.

12. The portable flash memory storage device according to claim 11, wherein the write operation performed by the firmware further comprises

an operation to read out data in a partially-written block;

an operation to erase the partially-written block;

an operation to merge the read-out data with new data to be written; and

an operation to write the merged data into the erased block.

13. The portable flash memory storage device according to claim 1, wherein said circuit further comprises a DC regulator circuit connected with said USB or IEEE 1394 connector and said flash memory module.

14. The portable flash memory storage device according to claim 1, wherein said microprocessor executes an initialization code of the firmware when said portable flash memory storage device is plugged into the USB or IEEE1394 port of the host computer.

15. The portable flash memory storage device according to claim 1, wherein said firmware enters into a waiting state after the execution of the initialization code.

16. The portable flash memory storage device according to claim 1, wherein the host computer automatically detects the device when it is plugged in and activates the driver, and wherein the driver executes initialization operations and instructs the host computer'"'"'s operating system to create a device symbol representing a removable storage device.

17. The portable flash memory storage device according to claim 1, wherein said microprocessor coordinates with the driver to accomplish initialization of the flash memory storage device when the device is plugged into the USB or IEEE1394 port of the host computer.

18. The portable flash memory storage device according to claim 17, wherein said initialization can include standard interface operation or special interface operation.

19. The portable flash memory storage device according to claim 1, wherein said establishing a data exchange channel further includes initialization of the firmware, the firmware awaiting a message from the driver, and thereafter exchanging messages between the firmware and the driver.

20. The portable flash memory storage device according to claim 1, wherein said device symbol enables a user to operate the portable flash memory storage device in the same way as a magnetic disk.

21. The portable flash memory storage device according to claim 1, wherein said device symbol enables a user to directly access the portable flash memory storage device.

22. The portable flash memory storage device according to claim 1, wherein the firmware receives said user requests to access the flash memory module from the driver that enables a user to operate the portable flash memory storage device in the same way as a magnetic disk.

23. The portable flash memory storage device according to claim 1, wherein said user requests to access the flash memory module are initially made at the host computer in magnetic disk format.

24. The portable flash memory storage device according to claim 1, wherein said user requests to access the flash memory module are received by the firmware without a communication protocol conversion.

25. The portable flash memory storage device according to claim 1, wherein said firmware receives said user requests to access the flash memory module that have been converted from a magnetic disk format.

26. The portable flash memory storage device according to claim 1, wherein the firmware receives an operation request from either the driver or the host computer'"'"'s operating system which indicates the presence of a device symbol on the host computer and wherein said device symbol enables a user to operate the portable flash memory storage device in the same way as a magnetic disk.

27. The portable flash memory storage device according to claim 1, wherein said device symbol display is removed when said flash memory storage device is disconnected from the host computer.

28. The portable flash memory storage device according to claim 9, wherein said software write protection detects the status of the write protection pin of the flash memory, and informs the write protection status to the driver.

29. The portable flash memory storage device according to claim 1, wherein said firmware is enabled to receive a special operation instruction from the driver for the portable flash memory device in the host computer, the special operation instruction having been converted from a user request in magnetic disk format.

30. The portable flash memory storage device according to claim 29, wherein the special operation instruction was converted from a user request in magnetic disk operation format without a communication protocol conversion.

31. The portable flash memory storage device according to claim 29, wherein the special operation instruction is received on the USB or IEEE 1394 connector in a standard USB packet or IEEE 1394 packet.

32. The portable flash memory storage device according to claim 29, wherein the special operation instruction further includes an erase command requiring an erase of a partially-written block and the firmware is enabled to read out any data to be saved in the partially-written block prior to erasing the partially-written block.

33. The portable flash memory storage device according to claim 32, wherein the data read out of the partially-written block can be merged with new data to be written to the erased block.

34. The portable flash memory storage device according to claim 32, wherein the merged data is written to the erased block.

35. The portable flash memory storage device according to claim 1, wherein said microprocessor further comprises a software for initialization, processing, and notification operations.