WO2007066285A2

WO2007066285A2 - A memory device

Info

Publication number: WO2007066285A2
Application number: PCT/IB2006/054606
Authority: WO
Inventors: Adrian Weston Payne; Richard John Caldwell; Leo Poll
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2005-12-07
Filing date: 2006-12-05
Publication date: 2007-06-14
Also published as: WO2007066285A3

Abstract

A memory device (10) comprises a main memory for storing data, an antenna for receiving wireless communications, a radio module connected to the antenna, a power supply for supplying power to the radio module and indicating means (20) connected to the radio module. The indicating means is arranged to output a visible or audible indication to the user in response to a communication received by the radio module, the communication including a reference to data stored by the main memory. A secondary memory may be provided on the memory device that stores information concerning the data stored on the main memory.

Description

DESCRIPTION

A MEMORY DEVICE FIELD OF THE INVENTION

This invention relates to a memory device and to a method of accessing a memory device.

BACKGROUND OF THE INVENTION

Portable memory devices are well known and widely used in many different environments. Consumer devices such as digital cameras and personal digital assistants (pdas) provide memory slots for rewritable media such as SD cards. These cards are small and lightweight and, as technology advances, can store relatively large amounts of data at a reasonable cost to the user. The cards have a physical interface that forms an electronic connection with a receiving slot on the device to which a user wishes to connect the card.

Other widely used portable memory devices include those utilising optical storage techniques, such as CDs and DVDs. Traditionally such devices were read only, but rewritable CDs and DVDs are now commonplace. A large amount of data can be stored in a robust and efficient manner.

Developments in these memory devices are occurring. For example, United States Patent Application Publication US 2002/0174337 discloses a memory card with a wireless communication function. The card includes a memory configured to rewritably store data, a communication unit configured to transmit/receive data via a wireless communication, an interface connectable to an external device, and a controller configured to execute direct access control to the memory via the communication unit. The controller is set in a direct access mode by a command supplied via the interface (or by an operation of a switch).

The provision of a wireless capability for the memory device allows the memory card to communicate wirelessly, when it is inserted in a device such as a pda. This allows the user, when normally writing data to the card, to have the option of transmitting that data over the wireless function of the memory card to a suitably wireless enabled receiver. However, the wireless function of the memory card can only be utilised when the card is connected to a suitable device that can provide power to the memory card.

Similarly, United States Patent Application Publication US 2001/0006902 discloses an IC card with a radio interface function, an antenna module. An SD memory card contains an RF circuit, a controller LSI and a flash memory. The RF circuit is connected to an antenna module attached to the SD memory card. The controller LSI executes radio interface control and interface control for the SD memory card. By running a protocol control program and an SD memory card interface control program stored in a ROM, using an MPU, the controller LSI executes upper-protocol control and SD memory card interface control (security data access control, flash memory access control).

As above, the wireless capability of the SD card allows the memory card to communicate wirelessly, when it is in contact with a device such as a pda. This allows the user to have the option of transmitting data over the wireless function of the memory card to a suitably wireless enabled receiver. However, as above, the wireless function of the memory card can only be utilised when the card is connected to a suitable host device that can provide power to the SD card.

Current memory cards are far from having enough capacity to store all the data that someone may wish to carry with them. In addition the cost rises dramatically with capacity. As capacity increases, people are buying new cards. Consequently, users will increasingly have many cards on which they store all their data. Cards are too small to be to effectively labelled. This presents the problem of trying to find the card that contains a particular file that is required. The current solution would be to put each card in turn into a memory card reader until the sought after file is found. As well as being time- consuming there is another problem that some card types (for example, TransFLASH) are not robust enough to be put in and out of memory card slots regularly.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to improve upon the known art.

According to a first aspect of the present invention, there is provided a memory device comprising a main memory for storing data, an antenna for receiving wireless communications, a radio module connected to the antenna, a power supply for supplying power to the radio module, indicating means connected to the radio module, the indicating means arranged to output an indication following receipt of a communication received by the radio module, the communication including a reference to data stored by the main memory.

According to a second aspect of the present invention, there is provided a method of accessing a memory device comprising a main memory for storing data, an antenna for receiving wireless communications, a radio module connected to the antenna, a power supply for supplying power to the radio module, and indicating means connected to the radio module, the method comprising the steps of receiving a communication at the radio module, the communication including a reference to data stored by the main memory and outputting an indication at the indicating means.

The communication including a reference to data stored by the main memory could be a query relating to a specific file name or be a more general query about such things as file types, for example. Other sorts of queries could concern the amount of free memory space on the memory device. The communication could also be part of a chain of messages, for example, asking the memory device to return data such as a list of the files stored, and then sending a further communication to the memory to output an indication depending upon the identification of a particular file.

Owing to the invention, it is possible to provide a memory card which has the same form factor as a standard memory card and which has a wireless transmission capability without first being connected to a host device to provide the power. The provision of the indicating means (such as a LED/buzzer/vibrator) as a means to communicate with a user allows the memory device to be queried wirelessly and to give directly to the user a signal. This is especially useful in situations where the user has multiple memory devices present and wishes to find the device containing a specific file, for example. None of the prior art documents describe a very low power radio link to provide file contents information from a self-contained memory card.

This invention solves a number of problems, for example, for a user not knowing which of multiple memory cards contains a particular file, or not knowing which files are stored on all memory devices. The invention provides a very low power consumption wireless radio frequency system into the memory device, with a battery of some form. The radio system can only operate at a low data-rate because it is optimized for low power consumption. This is enough to communicate, for example, the directory contents, though not necessarily to send the files themselves. The memory card is also given an LED, buzzer or vibrator as an indicating means to be used to send a simple signal. A separate device using the same wireless system can search for a particular file and then the memory card can signal that it contains the file.

One embodiment of the invention is to incorporate it into a standard SD card. Although SD cards are small, most conventional types still have unused space within the package. For example, a TransFLASH card is a smaller card which can be used in a compatible TransFLASH slot or can be placed inside a SD package adapter and then slotted into an SD card slot. Therefore there is room to put a radio module or radio integrated circuit and a slim battery or rechargeable cell for the power supply into a standard memory card such as an SD type.

When adding a radio system into the card, this can be done by adding a separate radio module or alternatively, the radio function could be more integrated with the memory card by reusing the card controller to control the radio. The registers and/or FLASH memory can be used as the memory for the radio system. The absolute requirement is that the radio system has some means of reading the Flash memory directory contents. The power supply capability will be very low voltage, peak current or amp-hours due to the necessity to use a physically small battery. Some form of energy scavenging could be used, such as having a solar cell on the outside of the memory card. Alternatively, or in addition, the power supply could recharge every time the card is connected to a memory card slot, taking power from a portable device with a much bigger battery or from the mains. The battery may be unable to supply the peak current requirements of the radio module, in which case the radio module could be operated intermittently using a power supply from a capacitor charged from the small battery.

The power supply may not be sufficient to power-up all the required functions of the memory card so that the file allocation table of the Flash memory can be interrogated and the directory contents worked out. A better solution may be to store the directory contents in a simple decoded format (such as ASCII) in a separate small memory, which could be within the radio module, every time the card is written to. The radio function could then just read this separate memory.

The signalling to the user can function in one of two ways. One method is that the separate wireless device can, for example, send a request for a particular file and then the card can initiate the signalling when it discovers that it contains the file that are being searched for. Alternatively, the separate wireless device can ask for the directory contents of each card and then instruct the relevant card to signal if it contains the required file. A flashing signal would be best, but buzzing or vibrating would also be possible if the power required to do this is low. In the former solution, the memory card radio function could, in theory, be receive only. However, this only provides the function of searching for a file and not finding out what the files are. After finding out what files all the cards contain the user can then choose a particular file and get the appropriate card to signal.

In one embodiment the memory device further comprises a controller for controlling access to the main memory, the main memory being a rewritable memory, with the power supply supplying power to the controller. The radio module is connected to the controller by a data connection. By powering the controller connected to the main memory and having that connected to the radio module, then the wireless interface can be used to query any information on the main memory of the memory card.

Advantageously, the memory device further comprises a secondary memory storing information on the data stored by the main memory. By providing a secondary memory, which can store a small amount of data in an efficient and low energy cost manner, it is possible to access information relating to the data stored on the main memory, without having to directly access the main memory itself. The data stored in the secondary memory could be a table of the files stored by the main memory, with such information as file size and file type stored with that information. The secondary memory could also be used to store associated information such as the number of files and the total memory capability of the main memory, and the extent to which there is free memory space within the main memory.

Preferably, the radio module is arranged to transmit a signal via the antenna, the signal comprising at least some of the information stored by the secondary memory. An advanced embodiment of the memory device can provide for two way communication via the antenna, which allows a separate device to query the memory device directly about the contents of the secondary memory.

Any suitable memory device can incorporate the invention. For example, any FLASH memory card such as Secure Digital (SD), CompactFlash (CF), MultiMedia Card (MMC), xD-picture card, Sony memory stick or SmartMedia is appropriate. In addition the invention could be used in any USB memory stick or any other form of portable memory.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:- Figures 1 to 5 are schematic views of five respective embodiments of a memory device, Figure 6 is a schematic diagram of a plurality of memory devices in communication with a host device, and

Figure 7 is a view similar to Figure 6 of the memory devices and the host device.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Figure 1 shows a first embodiment of a memory device 10, which is a modified SD card (information on SD cards can be found at www.sdcard.com). The memory device 10 includes a main memory 12 for storing data, an antenna 14 for receiving wireless communications, a radio module 16 connected to the antenna 14, a power supply 18 for supplying power to the radio module and indicating means 20 connected to the radio module 16. The memory card 10 further comprises a controller 22 for controlling access to the main memory 12, the main memory 12 being a standard FLASH rewritable memory.

The memory card 10 includes further components standard to an SD card including registers 24 and a copyright protection unit 26. The unit 26 uses Content Protection for Recordable Media (CPRM), a copyright protection technology used for the SD memory card. The card's control circuitry allows data to be read and written (in its protection area) only when appropriate external devices are detected.

The card 10 also includes a physical interface 28 for making a physical connection with an external read/write device, the physical interface 28 connected to the controller 22 by a data connection. Between the controller 22 and the physical interface 28 is an interface driver 30, and between the controller 22 and the main memory 12 is a memory interface 32. The SD card also includes a power-on detection unit 34 which is used to reset the SD card interface controller and FLASH memory interface.

The radio module 16 could be a System-in-Package module, an IC or several ICs co-operating together to provide the wireless functionality. In Figure 1 , the embodiment of the radio module 16 is shown as comprising a radio front-end IC 36, a baseband unit 38, a secondary memory 40 and a radio/SD interface 42. The radio module 16 is connected to the controller 22 by a data connection.

The secondary memory 40 stores information on the data stored by the main memory. The radio module (or IC) baseband processor 38 can interrogate the SD card interface controller 22 to get the FAT (FAT = file allocation table = file contents list) using the radio-SD interface 42. The secondary memory 40 is where FAT (which may be in a decoded form for easier reading) is stored.

The secondary memory 40 can be a simple EEPROM, which will use less power than reading from a larger FLASH EEPROM, and is easier to implement on the SD card 10. An alternative implementation is to just use the main FLASH EEPROM 12, and either to store a decoded FAT in a separate space in that main memory 12, or to just read the FAT when required. In this case a separate secondary memory 40 is not required.

The power supply 18, in the embodiment of Figure 1 , keeps only the radio module 16 powered. The power supply 18 is for the radio function of the card 10, and is recharged when the SD card 10 is connected to a host device. This can be achieved in a number of different ways. For example, the VDD pin of the physical interface 28 can be configured so that it supplies the power supply 18, or there can be provided some other form of energy scavenging. The power supply 18 is not necessarily on all the time; just enough power is needed to get an acceptable duty cycle on the radio link.

The indicating means 20, which is shown as an LED, is arranged to output an indication in response to a communication received by the radio module 16, the communication including a reference to data stored by the main memory 12. This is discussed in more detail below, with reference to Figures 6 and 7, but the principal purpose of the memory card 10 is to provide a way of transferring information to a user about the contents of the memory card 10.

The LED 20 can comprise several different coloured LEDs and the

LEDs can provide limited information to the user by lighting up, or blinking an intermittent pattern, or lighting up different colours. This is a similar interface to that commonly found on a device like a printer, which is providing detailed information in a relatively crude manner. Alternative ways of providing an indication to the user can be via a buzzer or vibrating device.

Figure 2 shows a second embodiment of the memory card 10. Throughout the respective five embodiments of Figures 1 to 5 the same numbers refer to the same components. In the embodiment of Figure 2, the radio module 16 and the SD card circuits are entirely separated. The power supply 18 keeps only the radio module 16 powered.

The radio module 16 is provided with the secondary memory 40 for storing, for example, the FAT containing the details of the files stored in the main memory 12. For the information to get to the secondary memory 40, the host device reads the main memory 12 of the SD card, accesses the FAT and transmits this wirelessly to radio module 16 where it is stored in the memory 40 for later retrieval.

The radio module 16 does not have the radio-SD card interface 42 of the embodiment of Figure 1. The overall design of this Figure 2 embodiment is simpler and requires less alteration to existing designs particularly of the SD card controller, although the radio module 16 no longer has direct access to the main memory 12.

Figure 3 shows a third embodiment of the memory device 10. In this embodiment, the radio module and SD card circuits are more combined. The controller 22 acts as both the radio baseband processor and the SD card interface controller.

The controller 22 also stores the FAT in the secondary memory 40. The power supply 18 is further for supplying power to the controller 22 in addition to the RF front end 36 of the radio module. The power supply 18 keeps the RF IC 36 and controller 22 powered. The indicating means 20 is also controlled directly by the controller 22, but the design of the circuitry still allows the secondary memory to be queried via the radio interface, without the need for the controller 22 to access the main memory 12.

Figure 4 shows a fourth embodiment of the memory device 10, which again is a modified SD card. The embodiment of this Figure is substantially identical to the embodiment of Figure 3, with the exception that the secondary memory is no longer provided. As before, the radio module and SD card circuits are more combined. The controller 22 acts as both the radio baseband processor and the SD card interface controller. The controller 22 also stores the FAT in the main memory. No separate memory chip is provided, the card 10 just uses the main FLASH memory. The power supply 18 keeps the RF IC 36 and the controller 22 powered.

A fifth embodiment of the memory device is shown in Figure 5, which shows an optical storage device 50, which could be a CD or a DVD and may be read only or have a writable or rewritable main memory 12 for storing data. An antenna 14 for receiving wireless communications is provided coiled around the inner non-recordable part of the CD, although other configurations are possible. A radio module is connected to the antenna 14, comprising the RF front end 36 and a baseband processor 38. The radio blocks shown are diagrammatic, in a practical embodiment, they are most likely be combined in a single module or IC.

A power supply 18 is provided for supplying power to the radio module, and indicating means 20 connects to the radio module. A secondary memory 40 is provided that is accessed by the baseband processor 38. The contents of the secondary memory 40 can be written at the time of manufacture of the CD, or, in the case of a writable or rewritable disc, they can be updated by the wireless connection provided through the antenna 14 and radio module. The secondary memory 40 is used to store information about the contents of the main memory 12, and this data can be queried wirelessly by another device.

The indicating means 20 could be mounted on the disk box in which the

CD or DVD is stored. This would result in an embodiment of the memory device 50 in which the disk box would glow when a user, for example, searches for a particular file. The interface between disc and disc box could be wireless or wired through a connection at the centre of the disc.

The memory devices 10 are shown in one example of their use in

Figure 6. In that Figure, three modified SD cards 10 are shown with a modified CD 50 in communication with a host device 44. The host device 44 could be a standard desktop PC with a wireless capability, or could be a pda with a similar wireless function. The host device 44 is provided with a wireless transceiver 46 for communicating with the memory devices 10 and 50.

No transmitter is required in the memory devices 10 or 50, which saves power and complexity in those devices. However, there is more complexity required in the radio module baseband processor 38 of each device as the processor must work out when the LED 20 should be lit.

The host device 44 is searching for a particular file and initiates a request to find the particular file, by transmitting a communication 48. The transceiver 46 transmits the file ID in the communication 48, which is received by each of the memory devices 10 and 50. The communication 48 includes a reference to data stored by the main memory.

The memory card 10 or CD 50 that contains the sought after file turns on its LED 20 to indicate the presence of the file on that storage medium. This allows a user to identify the memory device 10, 50 that is storing a specific file without having to insert each memory device 10, 50 into the host device 44 to search through the contents of the respective memory device 10, 50.

A second view of the operation of the memory devices 10 and 50 is shown in Figure 7. Again a host device 44 is provided with a transceiver 46. In addition, a transmitter is required in the memory devices 10 and 50, which uses more power and complexity. The radio module in each device 10 and 50 is arranged to transmit a signal via its antenna, the signal comprising at least some of the information stored by the secondary memory.

The radio module baseband processor 38, however, is reduced in complexity, as it just needs to respond to simple instructions, for example, transmit FAT, turn LED on or off.

In the methodology shown in Figure 7, the host device 44 initiates a request to find a particular file via the transceiver, by transmitting a communication 48. The communication 48 is a request for the FAT of each device 10 and 50, and is transmitted in a broadcast mode. The wireless memory devices 10 and 50 transmit back their FATs to the host device 44. The host device 44 decides, from interrogation of the FATs, which memory device 10 and 50 stores the desired file. The host device radio module 46 transmits (as indicated by the link 52) to the particular device 10, using an access code or handshake process, to instruct the single device 10 telling it to turn on its LED 20.

If the embodiment of memory devices 10 are as shown in Figure 2, or for memory device 50, then before the methodology shown in Figure 7 can take place, the memory 40 (Figure 2 or Figure 5) of the radio module 16 (Figure 2) must have been programmed with the current FAT. This is achieved when the wireless memory device 10 or 50 is connected to the host device 44. The host device 44 reads the main memory of the wireless memory device using the usual primary interface. The primary interface is, for example, the SD interconnects for an SD card embodiment, or the CD/DVD player for a CD/DVD embodiment. The FAT is decoded by the host device 44, in the usual manner, and transmitted wirelessly back in the required format to the wireless memory device 10 (using an access code or handshake process to be able to send instructions to the specific device) where it is stored in its memory 40 (Figure 2 or Figure 5) for later interrogation by the methodology shown in Figure 7 and described in the preceding paragraph.

The indicating means 20 (the LEDs 20 in Figures 1 to 7) in combination with the wireless capability of the memory devices 10 and 50 can be utilised in a number of different ways. The two examples discussed with reference to Figures 6 and 7 both use the indicating means 20 to indicate the location of a specific file. The same methodology can also be used to see whether a file exists or not. Other uses of the indicating means 20 include indicating whether a card/CD/DVD has little or a lot of free space, which can be achieved, for example by rate of blinking.

The methodology can also be used to indicate that a card/CD/DVD is empty, or to indicate that card/CD/DVD is full or non-writable (e.g. CD-R 'finished' state). Searches could also be executed to indicate cards/CDs/DVDs that contain certain file types, for example in response to search for *.mp3. Similarly, a search criterion can be defined to indicate cards/CDs/DVDs that contain files matching a search by date (for example, files modified in the last week).

The indicating means 20 can also be actuated to indicate to which card/CD/DVD was last written, to indicate cards/CDs/DVDs that contain files matching a search by size, to indicate number of files contained, to indicate ownership of cards/CDs/DVDs and to indicate cards/CDs/DVDs that are associated with a user's device either by having some kind of secure association to unlock the card/CD/DVD or simply because the files are written by the user or by the user's device. Alternatively, it can be used to indicate cards/CDs/DVDs that contain files associated with a user's device by having some kind of secure association to unlock the card/CD/DVD or simply because there are files written by the user or by the user's device.

Claims

1. A memory device comprising a main memory (12) for storing data, an antenna (14) for receiving wireless communications, a radio module

(16) connected to the antenna (14), a power supply (18) for supplying power to the radio module (16), indicating means (20) connected to the radio module (16), the indicating means (20) arranged to output an indication following receipt of a communication (48) received by the radio module (16), the communication (48) including a reference to data stored by the main memory (12).

2. A memory device according to claim 1 , and further comprising a controller (22) for controlling access to the main memory (12), the main memory (12) being a rewritable memory.

3. A memory device according to claim 2, wherein the power supply (18) is further for supplying power to the controller (22). 4. A memory device according to claim 2 or 3, wherein the radio module (16) is connected to the controller (22) by a data connection.

5. A memory device according to claim 2, 3 or 4, and further comprising a physical interface (28) for making a physical connection with an external read/write device, the physical interface (28) connected to the controller (22) by a data connection.

6. A memory device according to any preceding claim, and further comprising a secondary memory (40) storing information on the data stored by the main memory (12).

7. A memory device according to claim 6, wherein the radio module (16) is arranged to transmit a signal via the antenna (14), the signal comprising at least some of the information stored by the secondary memory (40). 8. A method of accessing a memory device comprising a main memory (12) for storing data, an antenna (14) for receiving wireless communications, a radio module (16) connected to the antenna (14), a power supply (18) for supplying power to the radio module (16), and indicating means (20) connected to the radio module (16), the method comprising the steps of receiving a communication (48) at the radio module (16), the communication (48) including a reference to data stored by the main memory (12) and outputting an indication at the indicating means (20).

9. A method according to claim 8, and further comprising storing, in a secondary memory (40), information on the data stored by the main memory

(12).

10. A method according to claim 9, and further comprising transmitting a signal via the antenna (14), the signal comprising at least some of the information stored by the secondary memory (40).