High security counter
AssigneeArachnid, Inc.
InventorJohn R. Martin
Life of this patent
Estimating the term…
Abstract
A high security counting system is shown for counting events represented by an event signal. The counting system includes a nonerasable programmable read only memory which is programmed by a programmer under the control of a controller. The controller is responsive to an event signal for controlling the programmer to program a bit from a first value to a second value wherein each bit programmed to a second value represents a unit of count and the number of bits programmed to the second value represents the count of said counter.
Claims16
A high security counting system for counting events represented by an event signal comprising:
- a programmable memory counter having a plurality of sequentially arranged memory locations, each memory location having a unique memory address and including a predetermined number of storage elements, each storage element being programmable from a first value to a second value and not programmable from said second value to said first value, the number of storage elements programmed to said second value representing the count of said programmable memory counter;
- a programmer coupled to said programmable memory counter;
- and
- a controller responsive to an event signal for controlling said programmer to program a storage element from said first value to said second value, wherein said controller controls said programmer to sequentially program the storage elements within a memory location by reprogramming a respective memory location a predetermined number of times equal to the number of storage elements at said memory location.
A high security counting system for counting events represented by an event signal comprising:
- a nonerasable programmable read only memory counter having a plurality of storage elements, each storage element being programmable from a first value to a second value, the number of storage elements programmed to said second value representing the count value of said nonerasable programmable read only memory counter;
- a random access memory counter adapted to store a count value;
- a programmer coupled to said programmable memory counter;
- and
- a controller responsive to an event signal for incrementing said random access counter by one unit and controlling said programmer to program a storage element from said first value to said second value, said controller further being adapted to compare the count value stored in said random access memory counter to the count value of said nonerasable programmable read only memory counter and produce an alarm signal if said count values are not equal.
A high security counting system for counting events represented by an event signal comprising:
- a nonerasable programmable read only memory counter having a plurality of sequentially addressable byte locations, each byte location including a predetermined number of bit locations, each bit location being programmable from a first value to a second value, the number of storage elements programmed to said second value representing the count of said counter;
- a programmer coupled to said memory counter;
- and
- a controller responsive to an event signal for controlling said programmer to program said bit locations from said first value to said second value by first selecting a byte location to be programmed and thereafter determining a bit location to be programmed by sequentially checking the bits within said selected byte location to determine if a respective bit location is set to said first value or said second value.
A high security counting system for counting events represented by an event signal comprising:
- a nonerasable programmable read only memory counter having a plurality of storage elements, each of which is programmable from a first value to a second value, the number of storage elements programmed to said second value representing the count of said counter;
- a random access memory counter adapted to store a count value;
- a programmer coupled to said programmable memory counter;
- and
- a controller for incrementing said random access counter by one unit in response an event signal and controlling said programmer to program a storage element from said first value to said second value every Nth time said random access counter is incremented, where N is a whole number greater than one.
Dependencies are inferred from the claim text.