Shift Register Memory Patents (Class 711/109)
  • Publication number: 20030023819
    Abstract: A data formatter includes a shift register and a pointer manager. The shift register receives data from a providing RAM and shifts that data in response to reading data from the providing RAM and writing data to a receiving FIFO. A pointer manager maintains a pointer that points to a first valid byte in a sub-block of data into the correct bytes lanes of the FIFO by moving the pointer as data is shifted into and out of the shift register.
    Type: Application
    Filed: November 30, 2001
    Publication date: January 30, 2003
    Inventors: Eric Peel, Bradley Roach, Qing Xue
  • Patent number: 6493794
    Abstract: In a large scale FIFO circuit comprising a shift register circuit, the shift register circuit is reduced in its occupation area size to reduce the entire size of the FIFO circuit. A necessary number N of addresses is divided by positive integers A, B, . . . , M (where A×B×. . . , ×M≧N) to form a plurality of small scale shift register circuits in each of an A address generation circuit (1), B address generation circuit (2), . . . , and, an M address generation circuit (3). An external input CLK (i.e., clock) signal is supplied to only one of the small scale shift register circuits, i.e., only the A address generation circuit. Of the remaining small scale shift register circuits, one has its address output signal supplied to its successors as a clock input signal by cascading the remaining small scale register circuits in connection, so that a plurality of the A addresses, B addresses, . . .
    Type: Grant
    Filed: May 18, 1999
    Date of Patent: December 10, 2002
    Assignee: NEC Corporation
    Inventor: Haruki Yamashita
  • Patent number: 6493287
    Abstract: A CAN microcontroller that supports a plurality of message objects, including a processor core that runs CAN applications, a CAN/CAL module that processes incoming messages, and a data memory space. The data memory space includes a plurality of message buffers associated with respective ones of the message objects, and a dedicated RAM memory space that contains a plurality of memory-mapped registers associated with each of the message objects. The plurality of memory-mapped registers associated with each message object correspond to respective command/control fields for facilitating configuration and setup of that message object. Each of the memory-mapped registers is mapped to a respective storage location within the dedicated RAM memory space. In one embodiment, the dedicated RAM memory space encompasses a plurality of separate RAM modules, each RAM module being dedicated to a respective one of the command/control fields.
    Type: Grant
    Filed: August 1, 2000
    Date of Patent: December 10, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Neil Edward Birns, William J. Slivkoff
  • Patent number: 6487630
    Abstract: According to an embodiment of the invention, a processor comprises a register file and a register stack engine. The register file has a predetermined size and a set of registers in the register file is allocated when a function in a code sequence is called. The register stack engine saves the contents of a set of registers in a reserve storage area responsive to a function call if the function call would overflow the predetermined size of the register file. The register stack engine restores data from the reserve storage area to the register file if a recursive function call occurs.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: November 26, 2002
    Assignee: Intel Corporation
    Inventor: Tuan H. Bui
  • Patent number: 6470439
    Abstract: The present invention relates to a FIFO (First In First Out) memory control circuit for controlling FIFO memory which is used in various electronic devices. Specifically, the present invention relates to a FIFO memory control circuit capable of performing asynchronous read/write control hen a write clock and a read clock are different and it is known or determined which of these clocks has a higher clock frequency.
    Type: Grant
    Filed: March 8, 2001
    Date of Patent: October 22, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Yamada, Koji Horikawa
  • Patent number: 6442646
    Abstract: A FIFO memory device for inputting/outputting data having variable lengths of the present invention, includes: a first holding portion for holding data having a maximum data length MAX of input data to be input to the FIFO memory device; a second holding portion for holding residue data having a data length shorter than the maximum data length; and an input selecting portion for selectively inputting the input data to the first holding portion and the second holding portion in accordance with a data length IBP of the residue data and a data length WB of the input data.
    Type: Grant
    Filed: March 30, 1998
    Date of Patent: August 27, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Hideyo Tsuruta
  • Patent number: 6434642
    Abstract: A structure and method for operating an asynchronous first in, first out (FIFO) memory system in which the full or empty condition of the memory is determined by comparing a currently-generated write address with a currently-generated read address and a next-to-be-used read address. The current write address and current read address are transmitted from a write address counter and a read address counter, respectively, to a flag control circuit. The flag control circuit includes registers for storing Gray-code versions of the current write address, the current read address, and the next-to-be-used read address, which is determined from the current read address. The flag control circuit generates intermediate ALMOST_EMPTY and ALMOST_FULL signals when the FIFO memory is one data value from being “empty” and “full”, respectively.
    Type: Grant
    Filed: October 7, 1999
    Date of Patent: August 13, 2002
    Assignee: Xilinx, Inc.
    Inventors: Nicolas J. Camilleri, Peter H. Alfke, Christopher D. Ebeling
  • Publication number: 20020103979
    Abstract: In order to enable a pointer register device including registers called shadow registers to conduct updating operation rapidly by arithmetic operation of a pointer value between the registers, a front/back register set includes a first register and a second register. A switch control section allows a read select switch and a write select switch to select different registers. When the read select switch selects the first register and the write select switch selects the second register, the sum obtained by an adder can be stored in the second register while retaining the pointer value of the first register. In this case, the pointer value need not be transferred between the registers.
    Type: Application
    Filed: January 29, 2002
    Publication date: August 1, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventor: Yoshihiro Koga
  • Patent number: 6415362
    Abstract: A method and system for performing write-through store operations of valid data of varying sizes in a data processing system, where the data processing system includes multiple processors that are coupled to an interconnect through a memory hierarchy, where the memory hierarchy includes multiple levels of cache, where at least one lower level of cache of the multiple of levels of cache requires store operations of all valid data of at least a predetermined size. First, it is determined whether or not a write-through store operation is a cache hit in a higher level of cache of the multiple levels of cache. In response to a determination that cache hit has occurred in the higher level of cache, the write-through store operation is merged with data read from the higher level of cache to provide a merged write-through operation of all valid data of at least the predetermined size to a lower level of cache.
    Type: Grant
    Filed: April 29, 1999
    Date of Patent: July 2, 2002
    Assignees: International Business Machines Corporation, Motorola, Inc.
    Inventors: James Nolan Hardage, Alexander Edward Okpisz, Thomas Albert Petersen
  • Patent number: 6404359
    Abstract: In a decoding system having a cache memory, for decoding a variable length code such as a MH code, the decoding is carried out by accessing the cache memory by using a variable length code as an address. Whether the cache memory is hit or mishit is judged by discriminating whether or not the code bits of the 7 bits succeeding to the firstly appeared “1” in the actual code is coincident with the tag stored in the cache memory. This comparison is carried out by masking bits other than an effective bit length of the actual code, by utilizing the three-bit information indicating the number of remaining bits in the actual code, succeeding to the firstly appeared “1”, outputted from the cache memory. Thus, the decoding system is capable of elevating the hit rate of the cache memory.
    Type: Grant
    Filed: May 30, 2000
    Date of Patent: June 11, 2002
    Assignee: NEC Corporation
    Inventor: Katsumi Sakai
  • Patent number: 6405269
    Abstract: A comparator circuit for detecting full and empty conditions in a first-in first-out (FIFO) memory system. The comparator circuit includes two-input logic circuits for comparing selected read and write addresses. An almost-empty condition is detected by comparing a next-to-be-used read address value with a currently-used write address value. When these address values are equal, high logic signals are passed by a set of mode control multiplexers to the select terminals of a series of carry chain multiplexers, thereby causing a high logic value to be transmitted to a data input terminal of a first register. The first register latches the high logic signal at the next rising edge of the read clock signal, thereby generating a high EMPTY control signal immediately after a final data value is read from the memory.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: June 11, 2002
    Assignee: Xilinx, Inc.
    Inventors: Nicolas J. Camilleri, Christopher D. Ebeling
  • Patent number: 6401148
    Abstract: A system and method for operating an asynchronous first in, first out (FIFO) memory system in which the amount of data stored in a FIFO memory is determined by re-synchronizing a binary read address from a read clock signal to a write clock signal, then subtracting the write-synchronized read address from the binary write address. The FIFO memory system includes the FIFO memory, read and write address counters for generating the binary read address and binary write address, respectively, and a write synchronization circuit. The binary read address is converted into a Gray-code value which is then synchronized to the write clock signal. The write-synchronized Gray-code read address value is then re-converted to binary to form the write-synchronized read address.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: June 4, 2002
    Assignee: Xilinx, Inc.
    Inventor: Nicolas J. Camilleri
  • Patent number: 6393531
    Abstract: A control queue for predicting, tracking and completing memory requests initiated by a memory controller in a computer memory. The control queue is loaded with the cycle by cycle control data necessary to complete the memory request. The control queue shifts its contents from one entry to the next on every clock cycle to the bottom entry of the queue. The control data from the bottom entry is used to generate signals and data to control the operation of the data path for the current clock cycle. The control queue also tracks and provides operational and timing dependency data to the memory controller so that operations can be initiated properly.
    Type: Grant
    Filed: February 25, 1999
    Date of Patent: May 21, 2002
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Stephen T. Novak, John C. Peck, Jr.
  • Patent number: 6389521
    Abstract: An image memory has a random access memory array capable of being randomly accessed; a serial access memory array partitioned into n power of 2 (n>1) divisional areas cyclically and serially accessed in asynchronism with the random access memory; data transfer unit for transferring data between the random access memory array and the serial access memory array; a determined unit for determining a row of data to be transferred from the random access memory array to each of the divisional areas; and a designating unit for designating at least one of a top serial access address and a last serial access address respectively of each divisional area, wherein the data transfer unit executes data transfer from the random access memory array to the serial access memory array in accordance with outputs from the determining unit and the designating unit.
    Type: Grant
    Filed: September 6, 2000
    Date of Patent: May 14, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Haruki Toda
  • Patent number: 6389490
    Abstract: A first in, first out (FIFO) memory system and method in which the full or empty condition of the FIFO memory is detected before the FIFO memory is actually full or empty, thereby allowing the generation of FULL or EMPTY control signals immediately after a last data value is written into or from the FIFO memory. An almost-empty condition, is detected by comparing the read address and write address values. When the read and write address values indicate that one data value remains in the FIFO memory and a read operation is about to be performed, an ALMOST_EMPTY control signal is applied to a data input terminal of a first register that is clocked by a read clock signal. The ALMOST_EMPTY control signal is latched by the first register at the next rising edge of a read clock signal, thereby causing the register to generate a high EMPTY control signal in the same read clock cycle during which the last data value is read from the FIFO memory.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: May 14, 2002
    Assignee: Xilinx, Inc.
    Inventors: Nicolas J. Camilleri, Peter H. Alfke
  • Patent number: 6389489
    Abstract: A data processor (102) includes a first-in, first-out (FIFO) buffer (110) having a variable threshold. The FIFO buffer (110) has a plurality of entries (200) for storing at least a portion of a data block that is to be transmitted through the FIFO buffer (110). To allow data blocks of varying size to be transmitted at different data rates, a variable threshold value for determining a maximum fullness of the FIFO buffer (110) is automatically calculated by the data processor (102) for each data block. This allows the data block to be transmitted through the FIFO buffer (110) as a continuous data stream, without interruption, from the data processor (102) to a data consumer. The variable threshold value is appended to a first entry of the data block along with start bits to indicate a beginning of the data block. The FIFO buffer (110) may include read and write counters (208, 212) and a comparator (210) for comparing a difference between read and write pointers and the variable threshold value.
    Type: Grant
    Filed: March 17, 1999
    Date of Patent: May 14, 2002
    Assignee: Motorola, Inc.
    Inventors: Chris Randall Stone, Ritesh Radheshyam Agrawal
  • Patent number: 6385717
    Abstract: A variety of applications do not require a high data throughput. The standardization of the interface in the field of smart cards fixes the processing width at 1 bit. Therefore, it is effective to use a programmable structure which operates with a data width of one bit. A data processing arrangement in the form of a 1-chip implementation with a processing width of 1 bit can be used in chip cards for simple control and automation functions while utilizing serial protocols. This structure features uncomplicated circuitry, a small chip surface area, a wide field of application and a low power consumption.
    Type: Grant
    Filed: August 17, 1999
    Date of Patent: May 7, 2002
    Assignee: U.S. Philips Corporation
    Inventor: Georg-Friedrich Mayer-Lindenberg
  • Patent number: 6370623
    Abstract: A multiport register file includes a first file unit having registers of a first width and a second file unite having registers of a second width. The second width being less than the first width. The first file unit accommodates data destined to be operands for functional units of a VLIW processor, or result data from those functional units. The second file unit accommodates guard bits for conditioning operation of those functional units.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: April 9, 2002
    Assignee: Philips Electronics North America Corporation
    Inventors: Vijay K. Mehra, Gerrit Ary Slavenburg
  • Patent number: 6366979
    Abstract: A memory circuit that allows for short retransmit recovery times by implementing a read cache memory in a FIFO device. A circuit comprising a memory array, a cache memory and a logic circuit. The memory array includes a read pointer, a write pointer and a plurality of memory rows. The cache memory is configured to store one or more memory data bits. The logic circuit is further configured to control the output of the circuit by presenting either (i) an output from the memory array or (ii) an output from the cache memory.
    Type: Grant
    Filed: December 16, 1997
    Date of Patent: April 2, 2002
    Assignee: Cypress Semiconductor Corp.
    Inventors: Pidugu L. Narayana, Daniel Eric Cress, Ping Wu
  • Patent number: 6353874
    Abstract: A method and apparatus for controlling and caching memory read operations is presented. A memory structure is used to store data for read operations in a manner that allows the data to be reused in order to respond to similar subsequent memory accesses. Circuitry is included that determines if data corresponding to read requests is currently buffered in the memory structure. If it is, no additional memory accesses over a bus are required to respond to the read request. If the data is not currently buffered, a read request is issued over the bus, and when the data is returned in response to the read request, it is placed in the memory structure for responding to the read request and possibly for responding to additional subsequent read requests.
    Type: Grant
    Filed: March 17, 2000
    Date of Patent: March 5, 2002
    Assignee: ATI International Srl
    Inventor: Stephen L. Morein
  • Patent number: 6317806
    Abstract: A queuing apparatus associated with a processor includes at least one static queue (11), an index generator (34), at least one index queue (37), and a static queue accessing arrangement. Each static queue (11) has a number of static queue locations (12), each for storing a static queue entry and an availability indicator (14) for indicating an availability status of the respective static queue location. The index generator (34) uses information from the static queue (11) to provide a unique index value for each static queue entry, the index value for a particular static queue entry identifying the static queue location (12) containing the particular static queue entry. Each index queue (37, 42) has a number of index queue locations (40), each for storing one of the index values provided by the index generator (34).
    Type: Grant
    Filed: May 20, 1999
    Date of Patent: November 13, 2001
    Assignee: International Business Machines Corporation
    Inventors: Srinath Audityan, Thomas Albert Petersen, Robert Charles Podnar
  • Patent number: 6279090
    Abstract: A system adaptively adjusts the phases of a plurality of internal clock signals, each respective internal clock signal causing a corresponding latch to store a digital signal responsive to the respective internal clock signal. The system includes a plurality of clock control circuits, each clock control circuit controlling the phase of a respective internal clock signal relative to a corresponding external clock signal responsive to a respective phase command signal. A plurality of evaluation circuits are coupled to the respective latches, each comparing the plurality of digital signals stored in the corresponding latch to expected values and generating a result signal indicating the results of this comparison. A phase selector circuit operates in a storage mode to sequentially develop a plurality of phase command signals on an output and store a corresponding result signal sequentially received on an input.
    Type: Grant
    Filed: September 3, 1998
    Date of Patent: August 21, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Troy A. Manning
  • Publication number: 20010014930
    Abstract: The invention relates to a new memory structure specially adapted for the storage of memory vectors. Each of the storage positions (#1, Mi-#M, Mi) of the memory has a length adapted to the length of large vectors and is parallelly arranged extending from an input and/or output for information and deeper into the memory. In this way each vector is stored undivided in a sequential order with the beginning of the vector at the input and/or output of the memory (memory field F1 in memory plane Mi). Addressing is made to the input and/or output of the memory. There are means (1IB-MIB, 1UB-MUB) acting like shift registers for the inputting and outputting of information in undivided sequence to/from the storage positions in the memory.
    Type: Application
    Filed: December 8, 1997
    Publication date: August 16, 2001
    Inventor: INGEMAR SODERQUIST
  • Patent number: 6263401
    Abstract: A computer-implemented method and apparatus for transferring the contents of a general register, in a register stack, to a location in a backing store in a main memory are described. When transferring the contents of a general register to a location in the backing store, the invention proposes collecting attribute bits included in each general register of a predetermined group of registers in a temporary collection register. Once the temporary collection register has been filled, the contents of this register are written to the next available location in the backing store. Similarly, on the restoration of registers from the backing store, a collection of attribute bits saved in the backing register is transferred to a temporary collection register. Thereafter, each attribute bit is saved together with associated data into a general register, thereby to restore the former contents of each general register.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: July 17, 2001
    Assignee: Institute for the Development of Emerging Architectures, L.L.C.
    Inventors: Jonathan K. Ross, Cary A. Coutant, Carol L. Thompson, Achmed R. Zahir
  • Patent number: 6256707
    Abstract: A cache DRAM includes a main memory, a main cache memory for storing data which is accessed at a high frequency out of data stored in the main memory, a main tag memory for storing an address in the main memory of the data stored in the main cache memory, a subcache memory for always receiving data withdrawn from the main cache memory for storage and supplying the stored data to the main memory when the main memory is in a ready state, and a subtag memory for storing an address in the main memory of the data stored in the subcache memory. Since the subcache memory serves as a buffer for data to be transferred from the main cache memory to the main memory, the main cache memory withdraws data to the subcache memory even if the main memory is in a busy state.
    Type: Grant
    Filed: March 18, 1999
    Date of Patent: July 3, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Tsukasa Ooishi
  • Patent number: 6233651
    Abstract: A large FIFO memory device has its total available memory capacity partitioned into memory sections. The partitions are in the form of programmable delimiters in order to determine flexibly the size of the memory sections.
    Type: Grant
    Filed: January 20, 1999
    Date of Patent: May 15, 2001
    Assignee: 3Com Technologies
    Inventors: Eugene O'Neill, Anne O'Connell
  • Patent number: 6230238
    Abstract: A method and apparatus for performing mis-aligned read and write operations to a stack involves providing a memory array (110). The memory array is split into a high byte memory array (116) and a low byte memory array (112). Each memory array (112 and 116) has its own bus interface unit (114 and 118) respectively. The high byte bus interface unit (118) increments the address bits to the high byte memory array (116) on every access to compensate for mis-aligned data. However, the low byte bus interface unit (114) does not increment the address value before accessing the memory array (112). By doing so, memory is read from the memory arrays (112 and 116) in either 8 bit sizes or 16 bit sizes regardless of whether the stack structure implemented in memory array (112 and/or 116) contains aligned data or mis-aligned data.
    Type: Grant
    Filed: March 2, 1999
    Date of Patent: May 8, 2001
    Assignee: Motorola, Inc.
    Inventors: John A. Langan, Bruce L. Morton
  • Patent number: 6230249
    Abstract: A first-in-first-out (FIFO) memory device includes a plurality of FIFO memory cores that contain a plurality of cells. A variable cell size circuit supports user programmable cell sizes in a FIFO memory device to permit selection of a wide range of cell sizes. The variable cell size circuit controls successive accesses to a cell in the memory device, and it resets a byte count when the byte count equals the cell size value to initialize the circuit for a subsequent access operation. The variable cell size circuit further includes a prediction circuit that indicates completion of access to the cell a predetermined number of counts prior to completion of the actual access. An alignment circuit generates data for write operations in cells that store an odd number of bytes per cell to compensate for the two byte per cell read operations. Each FIFO memory core includes a circuit that generates a cell available signal to indicate whether a cell in a corresponding FIFO memory core is available for reading.
    Type: Grant
    Filed: August 7, 1998
    Date of Patent: May 8, 2001
    Assignee: Integrated Device Technology, Inc.
    Inventors: Raymond K. Chan, Mario F. Au
  • Publication number: 20010000817
    Type: Application
    Filed: December 21, 2000
    Publication date: May 3, 2001
    Inventors: Masashi Hashimoto, Gene A. Frantz, John Victor Moravec, Jean-Pierre Dolait
  • Patent number: 6226713
    Abstract: A multi-level cache and method for operation thereof is presented for processing multiple cache system accesses simultaneously and handling the interactions between the queues of the cache levels. The cache unit includes a non-blocking cache receiving data access requests from a functional unit in a processor, and a miss queue storing entries corresponding to data access requests not serviced by the non-blocking cache. A victim queue stores entries of the non-blocking cache which have been evicted from the non-blocking cache, while a write queue buffers write requests into the non-blocking cache. Controller logic is provided for controlling interaction between the miss queue and the victim queue. Controller logic is also provided for controlling interaction between the miss queue and the write queue. Controller logic is also provided for controlling interaction between the victim queue and the miss queue for processing cache misses.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: May 1, 2001
    Assignee: Sun Microsystems, Inc.
    Inventor: Sharad Mehrotra
  • Patent number: 6175894
    Abstract: A command buffer for use in packetized DRAM includes a four stage shift register for shifting for sequentially storing four 10-bit command words. The shift register combines the four 10-bit command words into a single 40-bit command word and transfer the 40-bit command word to a storage register for processing by the DRAM. The shift register may then continue to receive and store subsequent 10-bit command words. The command buffer also includes circuitry for determining whether a command packet is intended for the memory device containing the command buffer or whether it is intended for another memory device. Specifically, a portion of the 40-bit command word from the storage register is compared to identifying data stored in an identifying latch. In the event of a match, a chip select signal is generated to cause the memory device to perform the function corresponding to other portions of the 40-bit command word.
    Type: Grant
    Filed: March 5, 1997
    Date of Patent: January 16, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Troy A. Manning
  • Patent number: 6167488
    Abstract: The present invention provides a stack management unit including a stack cache to accelerate data retrieval from a stack and data storage into the stack. In one embodiment, the stack management unit includes a stack cache, a dribble manager unit, and a stack control unit. The dribble manager unit maintains a cached stack portion, typically a top portion of the stack in the stack cache. The stack cache includes a stack cache memory circuit, one or more read ports, and one or more write ports. The stack management unit also includes an overflow/underflow unit. The overflow/underflow unit detects and resolves overflow conditions and underflow conditions. If an overflow occurs the overflow/underflow unit suspends operation of the stack cache and causes the spill control unit to store the valid data words in the slow memory unit or data cache unit. After the valid data in the stack cache are saved, the overflow/underflow unit equates the cache bottom pointer to the optop pointer.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: December 26, 2000
    Assignee: Sun Microsystems, Inc.
    Inventor: Sailendra Koppala
  • Patent number: 6157979
    Abstract: An FeRAM array replaces ROM, PROM, EPROM, and/or EEPROM in a programmable controlling device and thus provides non-volatile memory cells for code stores, data stores, registers (including peripheral registers), state machines and microcode (if included) in the device. The programmable controlling device contains a processor and non-volatile ferroelectric memory cells as well as a ferroelectric memory array. The array has a code store that holds a program to control the processor, a data store that stores temporary data from the processor, and one or more registers that hold data being manipulated by the processor. The code store, data store and registers are memory mapped onto the non-volatile ferroelectric memory array. The state machines and peripheral registers are made of ferroelectric memory cells. The programmable controlling device may also include microcode that cooperates with the processor to change the function of the processor.
    Type: Grant
    Filed: March 14, 1998
    Date of Patent: December 5, 2000
    Assignee: Advanced Technology Materials, Inc.
    Inventor: Philip C Barnett
  • Patent number: 6148391
    Abstract: Embodiments of the present invention provide a stack renaming method and apparatus for stack based processors. Using principles of the present invention, a stack can be accessed simultaneously by one or more functional units in a stack processor. The stack apparatus includes a stack renaming unit capable of renaming a logical stack address to a real stack address. Each logical stack address corresponds to a storage element in the stack renaming unit which stores a real stack address. A circular counter is used in the stack renaming unit to sequentially cycle through each of the logical stack addresses. The real stack addresses corresponding to each of the logical stack addresses can be stored out of order in the stack renaming unit. A stack control unit is coupled to the stack renaming unit and provides one or more control signals to the stack renaming unit and coordinates the operation of the stack renaming unit within the stack apparatus.
    Type: Grant
    Filed: March 26, 1998
    Date of Patent: November 14, 2000
    Assignee: Sun Microsystems, Inc.
    Inventor: Bruce Petrick
  • Patent number: 6145061
    Abstract: A circular queue is asynchronously accessed and managed by two separate processing elements. Each data element is added to the queue together with a zero data element that both marks the tail of the queue and signifies that the queue is empty. Data elements are removed from the queue in the order in which they were stored (first-in-first-out) and a manner that allows multiple, concurrent access to the queue. When the queue is accessed to remove a data element the element is first tested. If it is non-zero, the removal process continues; if zero, the queue is considered empty. The management of the queue permits dynamic re-sizing (i.e., making the queue larger or smaller) while data elements are being added and/or removed.
    Type: Grant
    Filed: January 7, 1998
    Date of Patent: November 7, 2000
    Assignee: Tandem Computers Incorporated
    Inventors: David J. Garcia, David P. Sonnier
  • Patent number: 6138227
    Abstract: A digital memory matrix having memory cells in rows and columns, addressing of the memory cells is accomplished by control devices which perform arbitrary jumps of address, thereby avoiding addressing on adjacent lines. The jump increment is selectable. The control devices are control chains, two of which are provided, and the outputs of the control chains are connected to linking elements that in turn are connected to the memory lines. The linking elements are provided in groups.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: October 24, 2000
    Assignee: Siemens Aktiengesellschaft
    Inventors: Roland Thewes, Doris Schmitt-Landsiedel, Paul-Werner von Basse, Michael Bollu
  • Patent number: 6134637
    Abstract: An image memory has a random access memory array capable of being randomly accessed; a serial access memory array partitioned into n power of 2 (n>1) divisional areas cyclically and serially accessed in asynchronism with the random access memory; data transfer unit for transferring data between the random access memory array and the serial access memory array; a determined unit for determining a row of data to be transferred from the random access memory array to each of the divisional areas; and a designating unit for designating at least one of a top serial access address and a last serial access address respectively of each divisional area, wherein the data transfer unit executes data transfer from the random access memory array to the serial access memory array in accordance with outputs from the determining unit and the designating unit.
    Type: Grant
    Filed: March 30, 1999
    Date of Patent: October 17, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Haruki Toda
  • Patent number: 6131144
    Abstract: The present invention uses a stack management unit including a stack cache to accelerate data retrieval from a stack and data storage into the stack. In one embodiment, the stack management unit includes a stack cache, a dribble manager unit, and a stack control unit. The dribble manager unit maintains a cached stack portion, typically a top portion of the stack in the stack cache. The stack cache includes a stack cache memory circuit, one or more read ports, and one or more write ports. The stack management unit also includes an overflow/underflow unit. The overflow/underflow unit detects and resolves overflow conditions and underflow conditions. If an overflow occurs the overflow/underflow unit resolves the overflow by suspending operation of the stack cache and spilling a plurality of data words from the stack cache to the stack and equating the bottom pointer to the optop pointer. Typically, the overflow/underflow unit spills all valid data words from the stack cache during an overflow.
    Type: Grant
    Filed: April 1, 1997
    Date of Patent: October 10, 2000
    Assignee: Sun Microsystems, Inc.
    Inventor: Sailendra Koppala
  • Patent number: 6125440
    Abstract: A controller for a digital processor includes a random access memory, e.g., an instruction memory, that consumes significant power when operating. To reduce the power consumption when repetitive instructions, i.e. loops, are being performed, the instructions being executed are stored in a shift register and, when a jump-back instruction is executed, the instructions, including those in the loop, are then accessed from the shift register rather than from the random access memory without any additional special instructions that define the characteristics of the loop. A memory control includes a state tracking machine that monitors the execution of the program instructions and determines from the execution of a jump-back instruction that a loop may have been entered, whereupon it enables the shift register to produce the instructions stored therein and disables the instruction memory from producing instructions that are stored in the shift register.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: September 26, 2000
    Assignee: Tellabs Operations, Inc.
    Inventor: Alexander Osovets
  • Patent number: 6092165
    Abstract: A programmable memory controller is described. The memory control signals and timings are defined by programmable means. A plurality of shift registers are loaded with programmed values at the start of a control sequence. The programmed values are synchronously shifted with the optimum value system clock to thereby generate a plurality of memory control signals. Each memory control signal is generated by a shift register. Depending on the mode of operation to be performed by the memory device, different programmed values are loaded into the plurality of shift registers at the start of a control sequence. The selection of which programmed value to be loaded into the plurality of shift registers is accomplished by a multiplexer device coupled with each shift register. The multiplexer device selects one input mode register containing programmed values. One input mode register exists for each mode of operation that can be performed by the memory device.
    Type: Grant
    Filed: August 16, 1996
    Date of Patent: July 18, 2000
    Assignee: Unisys Corporation
    Inventor: Philip C. Bolyn
  • Patent number: 6076136
    Abstract: A memory access system is provided for accessing a first data unit and a second data unit in a single memory access cycle. The memory access system provides at least a memory, an even address decoding circuit, an odd address decoder, and shift logic. The memory is interleaved by at least one address bus signal into an even memory bank and an odd memory bank. The even memory bank and the odd memory bank are each organized by a plurality of corresponding rows. Each one of the rows contains at least one storage location for a data unit, with one address mapped to one storage location. The even address decoding circuit decodes an address bus signal supplied to the input terminal and activates an output terminal coupled to enable the given row of the even memory bank. The odd address decoder decodes the address bus signal to activate an output terminal coupled to enable the row of the odd memory bank in which the first data unit resides.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: June 13, 2000
    Assignee: Lucent Technologies, Inc.
    Inventors: William G. Burroughs, Charles Raymond Miller
  • Patent number: 6073227
    Abstract: In order to move data blocks from a source memory unit (8, 9, 12) to a target memory unit (12, 8, 9) by means of a data path (5, 6, 7), wherein the blocks moved are not necessarily framed in the blocks of the source memory and the target memory, an electrical circuit makes it possible to perform a framing with a granularity equal to the width of the data path. To reduce latency, the framing is done by a shift register with a storage capacity reduced to that of a single block.
    Type: Grant
    Filed: June 2, 1997
    Date of Patent: June 6, 2000
    Assignee: Bull, S.A.
    Inventors: Jack Abily, Jean Yujun Qian
  • Patent number: 6067605
    Abstract: It is possible to continuously obtain the function of FILO for plural sets of data while reducing regions for storing the data. A string of data input from a memory M0 is shifted to a memory M3, and is switched back and read from the memory M0. Consequently, the function of FILO can be obtained for the same string. On the other hand, a string of data input from the memory M3 is shifted to the memory M0, and is switched back and read from the memory M3. Consequently, the function of FILO can also be obtained for the same string. With these two data strings keeping a push-pull relationship each other, the data are shifted among the memories M0 to M3. Therefore, the number of elements of each data string is enough for that of required memories.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: May 23, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masayuki Koyama, Naohiro Kobayashi
  • Patent number: 6065107
    Abstract: Systems are provided for saving register data in a pipelined data processing system, and for restoring the data to the appropriate register in the event of an exception condition. One embodiment concerns a latch feedback assembly, such as a SRL, which includes multiple series-connected latches having a feedback connection between last and first latches. The latches are clocked to temporarily reserve a delayed backup copy of data from the first latch on the last latch. Upon detection of an exception, the backup copy is first preserved by disabling writes to the last latch; then the backup copy is copied to the first latch to restore the first latch to its state prior to occurrence of the exception. Another embodiment involves a register file save/restore mechanism, in which an additional bank of registers, called a "backup register", is coupled to a register file. When data is stored in an address of the register file, the address and its data content are also stored in the backup register.
    Type: Grant
    Filed: August 28, 1998
    Date of Patent: May 16, 2000
    Assignee: International Business Machines Corporation
    Inventor: David Arnold Luick
  • Patent number: 6052757
    Abstract: A content-addressable, first-in/first-out memory (CAM-FIFO), as used to provide a read-modify-write buffer for data between two processes, includes: a Content Addressable Memory (CAM) which stores flag data; a FIFO memory portion for providing data storage; a write/read address counting section for providing write/read addresses of data to be stored in/read from the FIFO; and logic to determine and is used to query data on the queue to determine if the FIFO data should still be sent to the receiving process, or replaced with at least part of the flag data.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: April 18, 2000
    Assignee: Real 3D, Inc.
    Inventors: John Thomas Pedicone, Thomas Andrew Chiacchira, Andres Alvarez
  • Patent number: 6044431
    Abstract: Data buffering apparatus comprises a data memory in which input data are written to the memory in contiguous groups at memory addresses defined by a write pointer and data are read from the memory at a memory address defined by a read pointer; and means for writing a dummy group of data at the end of at least some of the input data groups, the dummy groups of data being read from the memory and discarded before a subsequently written input data group is read.
    Type: Grant
    Filed: April 9, 1997
    Date of Patent: March 28, 2000
    Assignees: Sony Corporation, Sony United Kingdom Limited
    Inventors: Jonathan Mark Greenwood, Michael John Ludgate
  • Patent number: 6041328
    Abstract: The present invention keeps track of available elements in a list of elements available to a given device for processing from an index and count mechanism. Such an index and count mechanism provides an index that indicates a starting element in the list of elements that is available to the given device for processing. Such an index and count mechanism also provides a count that indicates a subsequent number of elements, from the starting element in the list of elements, that are available to the given device for processing. A first index register and a second index register alternately keep track of a last available element in the list of elements available to be processed by the given device until the last available element is a very last element in the list of elements.
    Type: Grant
    Filed: December 17, 1997
    Date of Patent: March 21, 2000
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Ching Yu
  • Patent number: 6005820
    Abstract: A field memory having a distributed architecture is disclosed and in particular a memory arranged in block, wherein each block stores a bit or bits of said word, said bits having a predetermined position within said word. The distributed architecture improves the transfer of data between the input/output buffers and the internal registers of the memory. A data cache and an improved input erasable realisation are also disclosed.
    Type: Grant
    Filed: June 6, 1996
    Date of Patent: December 21, 1999
    Assignee: Texas Instruments Incorporated
    Inventors: Giuliano Imondi, Stefano Menichelli, Carlo Sansone
  • Patent number: 5996043
    Abstract: A command buffer for use in packetized DRAM includes a two stage shift register for shifting for sequentially storing two of the four 10-bit command words in each packet. After the first two words of each packet have been shifted into the shift register, they are transferred to a first storage register and output from the first storage register. After the final two words of each packet have been shifted into the shift register, they are transferred to a second storage register and output from the second storage register. The first two command words are output from the first storage register before the last two command words are applied to the command buffer. As a result, the DRAM can start processing the first two command words of the command packet before the entire command packet has been received. The command buffer also includes circuitry for determining whether a command packet is intended for the memory device containing the command buffer or whether it is intended for another memory device.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: November 30, 1999
    Assignee: Micron Technology, Inc.
    Inventor: Troy A. Manning
  • Patent number: 5983315
    Abstract: Each of a plurality of FIFO has (1) a low region indicating a minimum number of words for FIFO storage, (2) a burst count indicating the number of words involved in each transfer to such FIFO and (3) a high region where a word count transfer into the FIFO is not initiated. However, a burst count transfer initiated before the beginning of a FIFO high region may be completed in the FIFO high region. Each FIFO is initially filled from a memory by a memory controller to the low FIFO region. Upon word transfer from each FIFO, the memory controller establishes a priority to provide an additional burst count to the FIFO low region. When the memory controller is otherwise idle and the number of words in such FIFO is in a region intermediate the FIFO low and high regions, a burst count for each FIFO may be transferred into the intermediate FIFO region. The memory controller and each FIFO respectively remember the number of words transferred into and from such FIFO.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: November 9, 1999
    Assignee: Rockwell Science Center, Inc.
    Inventors: Steven P. Larky, Eric J. Fogleman