Advanced Micro Devices Corporation

Patrick T Chuang

Robert L Yau

Moon-Yee Wang

Hiroshi Yoshida

Paul D Keswick

Ron Maltiel

Lee-Lean Shu

George Marr

Darrell D Rinerson

Tai C Shyu

Jeffrey L Linden, Sr

Bill C Tung

Electrical buffer output circuitry includes a first high branch having a high signal input terminal, a low input branch having a low input signal input terminal, and a signal output for the buffer circuitry. Either the high branch or the low branch is turned on in response to a signal at one of the input terminals, and the resistance of the turned on branch is varied as a function of time to improve the speed and noise characteristics of the buffer until the output voltage stabilizes.

Noise reducing output buffer circuit with feedback path

A content addressable memory system includes a plurality of memory cells arranged in rows and columns in an array of N bit words by M word cells, a plurality of word lines extending through the array for addressing different words in the memory cells, each of the words comprising a plurality of adjacent cells extending in a first direction in the array, a plurality of match lines extending through the array in parallel with the word lines in the first direction, a plurality of bit lines extending through the array in a second direction perpendicular to the first direction, each of the bit lines communicating with the cells in one of the columns extending in the second direction, and a pair of registers connected to the bit lines for performing masking operations on bits in the array.

Content addressable memory array with priority encoder

A content addressable memory array includes an array of M words containing bits configured in N bits for each word. One of the bits in each of the words is a settable skip bit, and during a search of the memory array, the array is examined to detect the presence therein of skip bits. If a skip bit is detected in any one of the words, that word containing the detected skip bit is eliminated from the search. Each word in the array also contains an empty bit which is used to indicate an empty word location in the array. When all empty bits are set, the array is automatically reset to empty or zero.

Content addressable memory array with maskable and resettable bits

A content addressable memory system includes an array of memory cells arranged in rows and columns in an array of N bit cells by M words, with N bits per word, an I/O bus having a bit capacity S which is a submultiple of N, a mode generator for generating a plurality of commands, the commands including a command write command, a data write command, a data read command, and a status read command, the command write and the status read commands being encodable in S bits or less, and multiplexing means for supplying selected ones of the commands to the I/O bus.

Content addressable memory array system with multiplexed status and

A low power, low output impedance, CMOS voltage reference with high source/sink current driving capability. A CMOS current mirror preamplifier includes matched transistor pairs having their W/L ratios scaled to reduce the level of current to the subthreshold region. A CMOS source follower output stage also has its transistors biased in the subthreshold region. Circuitry for protecting the preamplifier from the effects of supply voltage and output voltage bumps is also disclosed.

Low power CMOS reference generator with low impedance driver

A nonvolatile dynamic RAM capable of operating in a dynamic RAM mode and a second, nonvolatile mode, is disclosed. The nonvolatile dynamic RAM has a memory cell having a transfer transistor for coupling a storage capacitor having a floating gate to a bit line. The memory cell holds information by the storage of charge in the storage capacitor and also holds information by the storage of charge in the floating gate. This data can be stored and retrieved in a volatile mode and in a nonvolatile mode. The nonvolatile dynamic RAM has a plurality of these memory cells connected to a bit line which, in turn, is connected to a sense amplifier for determining the presence or absence of storage charges in the storage capacitor of a selected memory cell in the first mode, and for determining the presence or absence of storage charges in the floating gate of the selected memory cell in the second mode.

Nonvolatile dynamic ram circuit

A non-volatile dynamic RAM circuit where each memory cell includes an access transistor, a floating gate structure, and a recall transistor connected in series between an I/O bit line and a common line. A conducting plate and storage node of the floating gate structure functions as the volatile storage element of the cell and the floating gate functions as the non-volatile storage element.

Non-volatile dynamic RAM cell

A plurality of capacitive memory elements are coupled between two pairs of bit line and return line halves. A cross-coupled MOSFET sense amplifier, configured to operate in a race mode, connects between the two bit line/return line pairs. The return line of each bit line/return line pair is coupled to the bit line of the other pair so that when any selected memory element is read to generate a data signal on the bit line half associated with that memory element, the complement of that data signal is coupled to the other bit line half via the return line to increase the signal level differential across the sense amplifier.

Capacitive memory signal doubler cell

An improved substrate bias generator is disclosed for use in a capacitive charge storage integrated circuit memory device having an external voltage supply. The generator comprises means for generating first and second timing signals, charge pumping means disposed for pumping positive charge from the substrate of the integrated circuit memory device in response to the first and second timing signals. Removal of the positive charge from the substrate polarizes the substrate at a negative potential, which is the generated bias voltage. A voltage regulation means is disposed between the output of the charge pumping means (i.e., the substrate) and the means for generating the timing signals. The voltage regulation means provides a reference potential that regulates the amount of charge pumped from the substrate as a function of the magnitude of the generated bias voltage. The voltage regulation means includes a voltage clamp circuit that is disposed for clamping the generated bias voltage to a limited negative value; a modulator circuit means disposed at the output of the voltage regulation means; and, a generator circuit means disposed at the output of the modulator circuit means for supplying the reference potential in response to the output voltage from the clamp circuit means as modified by the modulator circuit means.

Regulated substrate bias generator for random access memory

In source-clocked type of cross-coupled latch sense amplifier of a dynamic random access memory device, there is provided a sense clock that employs multiple extended dummy memory cells to provide reference timing which tracks time constants of word line, cell transfer gate, cell capacitor, and bit line, and the sense clock is further compensated over large variations of fabrication process parameters and operating conditions. The trigger and slave clock circuit are chained in series to control the timing sequence of a plurality of clocked output signals. The clocked output signals are selectively amplified and summed in parallel to generate current with an intended dynamic characteristic. The current so generated is applied to the common source electrodes of the cross-coupled latch.

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Cupertino, CA, United States of America

Patrick T Chuang