Motorola Corporation

Freescale Semiconductor,inc.

Eric V Fiene

Ravindraraj Ramaraju

Christopher Neal Hinds

George P Hoekstra

Troy L Cooper

Jogendra C Sarker

Daniel T Marquette

David P Burgess

Eric E Quintana

Gary A Mussemann

A memory management unit can receive an address associated with a page size that is unknown to the MMU. The MMU can concurrently determine whether a translation lookaside buffer data array stores a physical address associated with the address based on different portions of the address, where each of the different portions is associated with a different possible page size. This provides for efficient translation lookaside buffer data array access when different programs, employing different page sizes, are concurrently executed at a data processing device.

Multiple page size memory management unit

A system () translates memory addresses. Processing circuitry () provides an effective address to a storage array () having a plurality of stored effective addresses, each of the plurality of stored effective addresses having a corresponding pair of a lock bit and a valid bit. An output tag value and a single valid bit are provided to a comparator (). The lock bit defines one of two predetermined classes of tasks executed by the system. The single valid bit is applicable to both of the two predetermined classes of tasks. The lock bit qualifies the clearing of the single valid bit. The comparator respectively compares the output tag value and the single valid bit with a predetermined effective address and a predetermined bit value. An output hit signal is provided when a match occurs to validate a physical address provided by a physical address array ().

Data processing system having translation lookaside buffer valid bits with lock and method therefor

A method and apparatus for detecting and completing floating point operations involving special floating point operands is performed in parallel, via a circuit (24), to the operation of at least one floating point mathematical unit (18, 20or 22). The floating point control (30) along with registers (14 and 16) provide floating point operands and floating point control to the mathematical units (18, 20, and 22). If the mathematical units (18, 20, and 22) cannot perform a proper floating point calculation because of the presence of a special operand, then the circuit (24) will detect the special operand and complete the floating point operation in a proper manner by communicating with the floating point control unit (30).

Parallel method and apparatus for detecting and completing floating

In an integrated circuit microprocessor, an M-bit priority encoder circuit indicates the highest priority bit position that is set in a first portion of an N-bit (N generally being greater than M) data word and provides control information regarding the number of bits that are set. If more than one bit is set, the highest priority bit is reset, the first portion is re-analyzed, and highest priority bit information and control information are again provided. If only one bit or no bit is set in the first portion, a second portion is analyzed, and highest priority bit information and control information regarding the second portion is provided. Analysis of the second portion, and of any subsequent portions, continues in similar fashion until no further bit positions are determined to be set in the data word.

Partial-sized priority encoder circuit having look-ahead capability

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Austin, TX, United States of America

Eric V Fiene