Abstract: A system and method for determining a best match from a plurality of matches received in response to a search input for an associative memory includes a priority field associated with each data item stored in the associative memory. The priority field corresponds to criteria that is used to order the priority of the data items in the associative memory. A match resolution circuit is coupled to receive match signals from an associative memory, such as a CAM, and the priority fields of the matching data items. The match resolution structure compares the priority fields of the matching data items to determine which data item has the highest priority. The match resolution structure indicates the data item with the highest priority in the priority field as the best match of the associative memory for the particular search input.

Abstract: A circuit and method for reading and writing to a microprocessor's internal cache memory during a test mode of operation. During write accesses, an external data bus transmits to an internal data bus an address, cache tags and data in accordance with an external clock. During read accesses, the external data bus transmits an address and receives from the internal data bus data and cache tags. In one embodiment, during a write access, the external data bus is time-multiplexed to transmit an address, cache tags and data in two clock periods of the external clock the external data bus is time-multiplexed to transmit to the internal data bus an address in the first clock period of the external clock signal and to receive tag and data in the next successive clock periods of the external clock signal. In this embodiment, reserved pins are used to specify a cache access mode, including a test mode of operation.

Abstract: A structure and a method provide read and write access to a microprocessor's internal cache. During write access, an external data bus transmits to an internal data bus an address, cache tags and data in accordance with a clock provided externally. During read access, the external data bus transmits an address and receives from the internal data bus data and cache tags. In one embodiment, during write access, the external data bus is time-multiplexed to transmit an address, cache tags and data in two clock periods of an externally provided clock signal. During read access, the external data bus is time-multiplexed to transmit to the internal data bus an address in the first clock period of the external clock signal, and to receive tag and data in the next successive clock periods of the externally provided clock signal. In this embodiment, reserved pins are used to specify a cache access mode.

Abstract: A circuit improves the reliability of antifuses in certain types of systems by substantially eliminating the continuous undesirable applications of voltages across antifuse terminals. To accomplish this, an antifuse has applied across its two terminals a "reading" or "evaluation" voltage as required by the system operation for a single read or evaluation clock period (typically 5 ns to 30 ns in duration). The signal describing the state of the antifuse is then stored in a latch, register, or other suitable structure for subsequent sampling. In this manner, a low read current flows in the antifuse in response to the standard chip operating voltage for only a short period of time such as a single clock cycle. Thus, continuous voltages across the two terminals of the antifuse are avoided and an unprogrammed antifuse is not inadvertently programmed and a programmed antifuse is not inadvertently converted back to its high impedance state (i.e. "unprogrammed").

Abstract: An antifuse redundancy circuit operates with transparency to external circuitry and users. In one embodiment, an antifuse redundancy circuit incorporates two antifuses rather than one. The circuit is arranged so that both antifuses may be simultaneously programmed and read. If a single antifuse is programmed without programming the other antifuse, the antifuse redundancy circuit will register a programmed antifuse. Additionally, if a single programmed antifuse is unintentionally deprogrammed after both antifuses in the redundancy circuit have been programmed, the antifuse redundancy circuit will continue to register a programmed antifuse. The result is both an increase in manufacturing yield and an increase in the reliability of integrated circuits utilizing antifuses.

Abstract: Integrated circuit access times are reduced by an input structure in which input signals are routed through a low resistance path from the input pad directly to the interior of the integrated circuit without using an input driver.

Abstract: A circuit improves the reliability of antifuses in certain types of systems by substantially eliminating the continuous undesirable applications of voltages across antifuse terminals. To accomplish this, an antifuse has applied across its two terminals a "reading" or "evaluation" voltage as required by the system operation for a single read or evaluation clock period (typically 5 ns to 30 ns in duration). The signal describing the state of the antifuse is then stored in a latch, register, or other suitable structure for subsequent sampling. In this manner, a low read current flows in the antifuse in response to the standard chip operating voltage for only a short period of time such as a single clock cycle. Thus, continuous voltages across the two terminals of the antifuse are avoided and an unprogrammed antifuse is not inadvertently programmed and a programmed antifuse is not inadvertently converted back to its high impedance state (i.e. "unprogrammed").

Abstract: An antifuse redundancy circuit operates with transparency to external circuitry and users. In one embodiment, an antifuse redundancy circuit incorporates two antifuses rather than one. The circuit is arranged so that both antifuses may be simultaneously programmed and read. If a single antifuse is programmed without programming the other antifuse, the antifuse redundancy circuit will register a programmed antifuse. Additionally, if a single programmed antifuse is unintentionally deprogrammed after both antifuses in the redundancy circuit have been programmed, the antifuse redundancy circuit will continue to register a programmed antifuse. The result is both an increase in manufacturing yield and an increase in the reliability of integrated circuits utilizing antifuses.

Abstract: A method and structure for logically disconnecting an on-chip virtual-to-physical address translation unit from a microprocessor by holding the dynamic circuits of the translation unit in precharged state. In one embodiment, the method and structure provide a fixed remapping for the virtual address. A powering down of the translation unit effects power savings when the translation unit is not required.

Abstract: A high resolution sense amplifier and method for sensing the state of antifuses in an integrated circuit is capable of correctly reading even a defectively programmed antifuse having a resistance of up to 20 K.OMEGA. as being programmed. The sense amplifier reads two antifuses at each programmable location, and correctly reads that location as being programmed if either or both of the antifuses at that location have been blown.