Static information storage and retrieval – Addressing – Counting
Reexamination Certificate
1999-12-30
2001-10-02
Nelms, David (Department: 2818)
Static information storage and retrieval
Addressing
Counting
C365S185050, C365S185300
Reexamination Certificate
active
06298006
ABSTRACT:
BACKGROUND OF THE INVENTION
Non-volatile semiconductor or solid-state memories have the advantage of being fast, light-weight and low-power. Examples are ROM (read only memory), PROM (programmable read only memory), and EEPROM (electrically erasable programmable read only memory), which retain their memory even after power is shut down. However, ROM and PROM cannot be reprogrammed. EEPROM's have the advantage of being electrically writable (or programmable) and erasable. EEPROMs are used in electronic devices for storage of essential information which has to be maintained during power off and/or which has to be available when the electronic system is initialized. These semiconductor memories have been employed in small amounts for permanent storage of certain computer system codes or system parameters that do not change.
One common application of the use of an EEPROM is in network interface cards, such as those of the Next Generation Input/Output (NGIO) network interface card. In the interface cards, a controller needs access to non-volatile information which is established at the time of the board manufacturing. Examples of this non-volatile information includes a globally unique identification (GUID), the size of an external FLASH (if any), the subsystem vendor, the device identifications, and the configuration of the ports. The EEPROM can be programmed to store this information.
Board manufactures can generally choose what size EEPROM to include for each application. However, to access the information on the EEPROM, the controller on the board needs information on the size of the EEPROM. The size of the EEPROM has previously been communicated with the use of software or dedicated strapping pins. Each of these solutions increased the complexity of the boards and the cost of manufacturing, and did not allow the board designer to easily adjust the size of the EEPROM.
A system to provide flexibility in part selection for an interface card is desirable. This would allow various sizes of EEPROMS to be used with a controller, allowing the designer to minimize the number of interfaces supported. Additionally, if the size of the EEPROM was easily determined, the designer could select the least expensive EEPROM available.
SUMMARY OF THE INVENTION
The present invention automatically determines the size of an EEPROM in a circuit. A controller is connected to the EEPROM with both a “data to” the EEPROM connection and a “data from” the EEPROM connection. The controller begins to send logical low address bits over the “data to” the EEPROM connection. After each address bit is transmitted, the controller increments the value of a counter. The controller continually monitors the data from the EEPROM connection to determine when the EEPROM has been successfully addressed. Once the EEPROM receives the appropriate number of address bits to fully address the first address location, the EEPROM drives the “data from” connection low. The controller then uses the value of the counter to determine the size of the EEPROM. The controller may either calculate the size of the EEPROM or use the value of the counter in a look-up table.
One aspect of the present invention defines a method of determining a size of an EEPROM that includes providing an address bit to the EEPROM, incrementing a value of a counter, repeating the providing and the incrementing until the EEPROM responds, and determining the size of the EEPROM from the value of the counter.
REFERENCES:
patent: 4468729 (1984-08-01), Schwartz
patent: 4926314 (1990-05-01), Dhuey
patent: 5003506 (1991-03-01), Itaya
patent: 5175836 (1992-12-01), Morgan
patent: 6003121 (1999-12-01), Wirt
Collins Brian M.
Reohr, Jr. Richard D.
Auduone Gene N.
Fish & Richardson PC
Intel Corporation
Nelms David
LandOfFree
Method and apparatus to automatically determine the size of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus to automatically determine the size of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus to automatically determine the size of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2595968