Device having data storage

Abstract

The present invention relates to the field of devices which store data for a period of time. In one form, the invention relates to devices which store data in which the data store is subject to periodic and/or relatively short power outages. In one example, the invention relates to a radio frequency identification (“RFID”) transponder, and more particularly to a RFID transponder that is used in orientation independent applications. Other applications of the present invention are to devices used where supply power is intermittent. In a first aspect of embodiments described herein there is provided a.method of and/or device comprising a memory adapted to store data, a supply of power adapted to provide supply power to the memory, a path of leakage, the leakage path serving, over time, to diminish the integrity of data stored in the memory, and a leakage attenuator adapted to selectively attenuate the rate of leakage.

1 . A device comprising
 a memory adapted to store data   a supply of power adapted to provide supply power to the memory,   a path of leakage, the leakage path serving, over time, to diminish the integrity of data stored in the memory, and   a leakage attenuator adapted to control attenuation of the rate of leakage.   
     
     
         2 . A device as claimed in  claim 1 , wherein the leakage attenuator is adapted to enable selection of the degree of attenuation of the rate of leakage. 
     
     
         3 . A device as claimed in  claim 1 , wherein the leakage attenuator is a form of multistage switch, such as one or more MOSFETs. 
     
     
         4 - 5 . (canceled) 
     
     
         6 . A device as claimed in  claim 1 , wherein the leakage attenuator serves to reduce, attenuate and/or control leakage associated with a memory in a transponder. 
     
     
         7 - 9 . (canceled) 
     
     
         10 . A device as claimed in  claim 1 , wherein the memory comprises at least one memory cell. 
     
     
         11 . (canceled) 
     
     
         12 . A device as claimed in  claim 1 , wherein the leakage is sub-threshold leakage. 
     
     
         13 - 16 . (canceled) 
     
     
         17 . A device as claimed in  claim 1 , wherein the device is a transponder. 
     
     
         18 . A device as claimed in  claim 17 , wherein the device is an RFID transponder. 
     
     
         19 . (canceled) 
     
     
         20 . A method of controlling leakage in a device comprising:
 a memory adapted to store data;   a supply of power adapted to provide supply power to the memory;   a path of leakage, the leakage path serving, over time, to diminish the integrity of data stored in the memory, the method comprising the steps of:
 providing a leakage attenuator adapted to control the rate of leakage, the leakage attenuator being associated with a leakage path of the memory. 
   
     
     
         21 . A method as claimed in  claim 20 , where the leakage attenuator reduces sub-threshold leakage. 
     
     
         22 . A method as claimed in  claim 20 , further comprising the step of providing a multistage switch as the leakage control device. 
     
     
         23 . (canceled) 
     
     
         24 . A method as claimed in  claim 20 , wherein the leakage attenuator is a plurality of switches. 
     
     
         25 . A method as claimed in  claim 20 , wherein the leakage attenuator applies threshold adjustment. 
     
     
         26 . A method as claimed in  claim 25 , wherein the leakage attenuator also combines the use of the method as claimed in  claim 20 . 
     
     
         27 . A method as claimed in  claim 20 , further comprising controlling the leakage in a manner which enables data stored in the memory to remain valid for a period of time longer than an outage of power associated with the memory. 
     
     
         28 . A method as claimed in  claim 20 , further comprising applying the method to a transponder, such as an RFID transponder or a passive device. 
     
     
         29 . A system adapted to store data comprising a device as claimed in  claim 1 . 
     
     
         30 . Apparatus adapted to controlling leakage in a device, said apparatus including:
 processor means adapted to operate in accordance with a predetermined instruction set,   said apparatus, in conjunction with said instruction set, being adapted to perform the method as claimed in  claim 20 .   
     
     
         31 . (canceled) 
     
     
         32 . A device as claimed in  claim 1 , wherein the time is less than 10 minutes, preferably less than 1 minute, more preferably less than 1 second, even more preferably more than 50 msec. 
     
     
         33 . A method as claimed in  claim 20 , wherein the time is less than 10 minutes, preferably less than 1 minute, more preferably less than 1 second, even more preferably more than 50 msec. 
     
     
         34 - 35 . (canceled)