Patents Represented by Attorney John G. Graham
  • Patent number: 4554643
    Abstract: An electrically programmable read only memory or EPROM is formed by an MNOS process compatible with N-channel silicon gate manufacturing methods. Row address lines and gates are second level polysilicon, and output and ground lines are defined by elongated N+ regions formed beneath thin field oxide. Each storage cell is an MNOS transistor having an enhancement mode MOS transistor in series with it. The gates of the MNOS transistors are program address lines for programming and are formed by first level polycrystalline silicon. Each MNOS transistor in the array is programmed to be a logic "1" or "0" by proper voltages applied to row, output and program address lines to store charge at the oxide-nitride interface and thus change the threshold voltage for selected transistors. Then readout is provided using the MOS series transistors for access. A very dense array results.
    Type: Grant
    Filed: July 8, 1982
    Date of Patent: November 19, 1985
    Assignee: Texas Instruments Incorporated
    Inventor: Chang-Kiang Kuo
  • Patent number: 4547868
    Abstract: A semiconductor dynamic read/write memory circuit using one-transistor storage cells and balanced bit lines with differential sense amplifiers employs dummy capacitors which are the same size as the storage capacitors. The dummy cell produces a signal on the bit line half that of the storage cell due to a level-shift circuitry connected to the dummy cells. The dummy capacitor is precharged to a reference voltage, and at the beginning of an active cycle the dummy capacitor is charge-shared with another capacitance of the same size, to change the reference level. The net signal is thus equal to that of a capacitor one-half the size of the storage capacitors.
    Type: Grant
    Filed: July 26, 1984
    Date of Patent: October 15, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Jimmie D. Childers, Adin E. Hyslop
  • Patent number: 4544416
    Abstract: A method of removal of photoresist in a manufacturing process for semiconductor devices utilizes burnoff in an oxidizing atmosphere. In order to reduce contamination of underlying silicon dioxide layers, chlorine in the atmosphere getters Na+ ions, etc. The chlorine gas is obtained from HCL added to the oxidizing atmosphere.
    Type: Grant
    Filed: August 26, 1983
    Date of Patent: October 1, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Charles G. Meador, Eddie H. Breashears
  • Patent number: 4543501
    Abstract: A random access read/write MOS memory device consisting of an array of rows and columns of one-transistor memory cells employs a bistable sense amplifier circuit at the center of each column. The sense amplifier is of the dynamic type in that coupling transistors connect the column line halves to the cross-coupled driver transistors. The sources of the driver transistors are connected to ground through a sequentially timed, three step grounding arrangement employing two transistors, one having a dual channel implanted to provide two different threshold voltages. Active load devices connected to the column line halves provide pull-up of the voltage on the one-going column line half to a full Vdd level.
    Type: Grant
    Filed: October 15, 1984
    Date of Patent: September 24, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Joseph C. McAlexander, III, Lionel S. White, Jr., G. R. Mohan Rao
  • Patent number: 4543500
    Abstract: A random access read/write MOS memory device consisting of an array of rows and columns of one-transistor memory cells employs a bistable sense amplifier circuit at the center of each column. The sense amplifier is of the dynamic type in that coupling transistors connect the column line halves to the cross-coupled drive transistors. The sources of the driver transistors are connected to ground through a sequentially timed, three step grounding arrangement employing two transistors, one having a dual channel implanted to provide two different threshold voltages. Active load devices connected to the column line halves provide pull-up of the voltage on the one-going column line half to a full Vdd level.
    Type: Grant
    Filed: October 22, 1980
    Date of Patent: September 24, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Joseph C. McAlexander, III, Lionel S. White, Jr., G. R. Mohan Rao
  • Patent number: 4542453
    Abstract: A single-chip microcomputer device contains on-chip program storage in a read-only memory (ROM), and this program may be corrected or updated by patching. The ROM addresses are applied to an off-chip memory device containing one bit for each potential ROM address, and each bit is set to mark the beginning address of code to be patched; an interrupt is signalled when one of these set bits is accessed by an address occurring during operation of the microcomputer. The interrupt causes the processor to branch to an off-chip program memory to insert the patch code. The patch ends in a branch back to the on-chip ROM.
    Type: Grant
    Filed: February 19, 1982
    Date of Patent: September 17, 1985
    Assignees: Texas Instruments Incorporated, IBM Corp.
    Inventors: Michael J. Patrick, David M. Snider
  • Patent number: 4538239
    Abstract: A system for real-time digital signal processing employs a single-chip mircocomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances. The internal busses are 16-bit, while the ALU and accumulator are 32-bit. An improved multiplier circuit produces a single state 16.times.16 multiply function separate from the ALU, with 32-bit output to the ALU; an array of static adders with carry feed-forward controlled by two-bit-at-a-time Booth's decoders, along with a dynamic carry-ripple adder, produces the one-state 16.times.16 multiply. One input to the ALU passes thorugh 0-to-15 bit shifter with sign extension.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: August 27, 1985
    Assignee: Texas Instruments Incorporated
    Inventor: Surendar S. Magar
  • Patent number: 4533843
    Abstract: A random access read/write MOS memory device consisting of an array of rows and columns of one-transistor memory cells employs a bistable sense amplifier circuit at the center of each column. The sense amplifier is of the dynamic type in that coupling transistors connect the column line halves to the cross-coupled driver transistors. The sources of the driver transistors are connected to ground through a sequentially timed, three step grounding arrangement employing two transistors, one having a dual channel implanted to provide two different threshold voltages. Active load devices connected to the column line halves provide pull-up of the voltage on the one-going column line half to a full Vdd level.
    Type: Grant
    Filed: October 15, 1984
    Date of Patent: August 6, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Joseph C. McAlexander, III, Lionel S. White, Jr., G. R. Mohan Rao
  • Patent number: 4533992
    Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances. The internal busses are 16-bit, while the ALU and accumulator are 32-bit. A multiplier circuit produces a single state 16.times.16 multiply function separate from the ALU, with 32-bit output to the ALU. One input to the ALU passes through a 0-to-15 bit shifter with sign extension.
    Type: Grant
    Filed: February 22, 1982
    Date of Patent: August 6, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Surendar S. Magar, Edward R. Caudel
  • Patent number: 4528625
    Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data. An external program address bus allows the alternative of off-chip program fetch in each instruction cycle, with the opcode returned by an external data bus. Data I/O instructions for access to peripherals or external data memory use two machine cycles so that the external ROM fetch is not distributed. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances. The internal busses are 16-bit, while the ALU and accumulator are 32-bit. A multiplier circuit produces a single state 16.times.16 multiply function separate from the ALU, with 32-bit output to the ALU. One input to the ALU passes through a 0-to-15 bit shifter with sign extension.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: July 9, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Kevin C. McDonough, Surendar S. Magar
  • Patent number: 4521701
    Abstract: A clock circuit for producing a high-level delayed clock output following an input clock employs an output transistor and pull-down transistor controlling an output node in response to the voltage on a drive node. The input clock is applied to this drive node by a decoupling arrangement, consisting of two series transistors. The first transistor isolates the input charge on a holding node, and the second of the series transistors transfers the charge to the drive node after the desired delay. The output node is held at zero until after the delay, with no unwanted voltage rise, and no d.c. power loss. A large capacitive load can be driven.
    Type: Grant
    Filed: September 16, 1982
    Date of Patent: June 4, 1985
    Assignee: Texas Instruments Incorporated
    Inventor: Chitranjan N. Reddy
  • Patent number: 4519031
    Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data; however, the accumulator in the data path may be used as a program address source for table look-up, for example. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances, such as accumulator addressing. The internal busses are 16-bit, while the ALU and accumulator are 32-bit. A multiplier circuit produces a single state 16.times.16 multiply function separate from the ALU, with 32-bit output to the ALU. One input to the ALU passes through a 0-to-15 bit shifter with sign extension.
    Type: Grant
    Filed: February 22, 1982
    Date of Patent: May 21, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Surendar Magar, Wanda K. Gass
  • Patent number: 4514897
    Abstract: An N-channel, double level poly, MOS read only memory or ROM array is electrically programmable by floating gates positioned beneath control gates formed by row address lines. The cells may be electrically programmed by applying selected voltages to the source, drain, control gate and substrate; the floating gate is charged through an insulator between the floating gate and the channel. A simplified process for fabrication of the devices eliminates photoresist and implant steps yet produces improved characteristics in the form of higher gain and lower body effect.
    Type: Grant
    Filed: April 26, 1984
    Date of Patent: May 7, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Te-Long Chiu, Jih-Chang Lien
  • Patent number: 4514801
    Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data; however, the accumulator in the data path may be used as a program address source for table-read and table-write, for example. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances, such as accumulator addressing. The internal busses are 16-bit, while the ALU and accumulator are 32-bit. A multiplier circuit produces a single state 16.times.16 multiply function separate from the ALU, with 32-bit output to the ALU. One input to the ALU passes through a 0-to-15 bit shifter with sign extension.
    Type: Grant
    Filed: February 22, 1982
    Date of Patent: April 30, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Edward R. Caudel, Gary L. Swoboda, Surendar S. Magar, Kevin C. McDonough, Antony W. Leigh
  • Patent number: 4514805
    Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data; however, the accumulator in the data path may be used as a program address source for table look-up for accumulator addressing, for example. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. The on-chip program memory may be disabled and only off-chip memory used for program fetch in a systems emulator mode. A non-maskable interrupt procedure used in the emulator mode generates a vector address for the on-chip ROM in switching between memory expansion and emulator modes, using an overvoltage detector to signal this condition.
    Type: Grant
    Filed: February 22, 1982
    Date of Patent: April 30, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Kevin C. McDonough, Gary L. Swoboda, Surendar S. Magar
  • Patent number: 4509142
    Abstract: A semiconductor memory device contains an on-chip self-incrementing counter which may be loaded from address input terminals, so that the memory cell array may be accessed using either an incoming address or the last address incremented by one. Also, the incremented last address is saved in a latch. A comparator receives the present address and incremented last address, and if these match a data output is available immediately. After a read cycle, the array is always accessed using the incremented last address, so when another fetch is initiated from the CPU, if it is for the next sequential address, the data is already available in a data ouput latch and the apparent access time is much less than that of the memory array.
    Type: Grant
    Filed: December 15, 1982
    Date of Patent: April 2, 1985
    Assignee: Texas Instruments Incorporated
    Inventor: Jimmie D. Childers
  • Patent number: 4508978
    Abstract: In a clock generator circuit for a dynamic RAM or the like it is necessary to boot certain nodes to a value to above the supply voltage in order to provide a high-level gate voltage for output transistors. To prevent excess voltage on the gate oxide of a transistor connected to a booted node, a series transistor is added which has the supply voltage on its gate, so neither transistor will have the full booted voltage across its gate oxide.
    Type: Grant
    Filed: September 16, 1982
    Date of Patent: April 2, 1985
    Assignee: Texas Instruments Incorporated
    Inventor: Chitranjan N. Reddy
  • Patent number: 4507853
    Abstract: Metal contacts and interconnections for semiconductor integrated circuits are formed by a process of two metal depositions to increase step or sidewall coverage. After a first layer of metal is deposited, a preferential etch removes all of the metal except on the vertical sides of steps or apertures. A second layer of metal is deposited over the remaining parts of the first, resulting in smoother transistions and greater thickness at steps.
    Type: Grant
    Filed: August 23, 1982
    Date of Patent: April 2, 1985
    Assignee: Texas Instruments Incorporated
    Inventor: James M. McDavid
  • Patent number: 4507727
    Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program and data. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances; for example, the internal program ROM may be read out on the data bus, one opcode at a time for test purposes, without executing the opcodes.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: March 26, 1985
    Assignee: Texas Instruments Incorporated
    Inventor: Surendar S. Magar
  • Patent number: 4507757
    Abstract: A programmable device is provided by a thin-oxide avalanche fuse element which is programmed at a voltage below the oxide breakdown level. This device may be used in a memory array of the PROM type. Upon breakdown, the thin oxide is perforated by small holes which fill with silicon to create short circuit.
    Type: Grant
    Filed: March 23, 1982
    Date of Patent: March 26, 1985
    Assignee: Texas Instruments Incorporated
    Inventor: David J. McElroy