Abstract: A semiconductor memory device has 2n word lines, a plurality of bit lines, a plurality of nonvolatile memory cells disposed at each intersection of the word lines and the bit lines, a write circuit for writing data to a memory cell located at an intersection of selected ones of the word lines and the bit lines, and a sense amplifier for reading data out of the memory cells. Further, the semiconductor memory device comprises a first unit for simultaneously selecting a block of 2m (n>m) word lines among the 2n word lines, and a second unit for not selecting a block of 2k (m>k) word lines among the 2m word lines. The second unit does not select the block of 2k word lines, and selects a block of 2k word lines prepared outside the 2n word lines when any one of the 2k word lines among the 2m word lines is defective. Consequently, redundant word lines are effectively employed, write and verify operations are stable, and thereby the yield and performance of the semiconductor memory device are improved.

Abstract: A semiconductor memory device has 2n word lines, a plurality of bit lines, a plurality of nonvolatile memory cells disposed at each intersection of the word lines and the bit lines, a write circuit for writing data to a memory cell located at an intersection of selected ones of the word lines and the bit lines, and a sense amplifier for reading data out of the memory cells. Further, the semiconductor memory device comprises a first unit for simultaneously selecting a block of 2m (n>m) word lines among the 2n word lines, and a second unit for not selecting a block of 2k (m>k) word lines among the 2m word lines. The second unit does not select the block of 2k word lines, and selects a block of 2k word lines prepared outside the 2n word lines when any one of the 2k word lines among the 2m word lines is defective. Consequently, redundant word lines are effectively employed, write and verify operations are stable, and thereby the yield and performance of the semiconductor memory device are improved.

Abstract: A multiple purpose bus for a flash memory device that allows six sets of data signals to utilize the bus. The multiple purpose bus includes sixteen circuit lines that extend from one end of the memory device to another end of the memory device. Control signals that correspond to each set of data signals couple the sets of data signals to the circuit lines. A grounding circuit is provided that couples the circuit lines to a ground when none of the sets of data signals are utilizing the multiple purpose bus.

Abstract: Nonvolatile semiconductor memory has a core-side cell array having word lines, bit lines and memory cells; a reference-side cell array having word lines, bit line, and reference cell; and, a sense amplifier which compares a core-side input voltage corresponding to a bit line current in the core-side cell array, and a reference-side input voltage corresponding to the bit-line current in the reference-side cell array. The core-side decoder-driver and reference-side decoder-driver drive the core-side and reference-side word lines to the power supply voltage at a first time at the end of the address change detection pulse, and, at a second time a prescribed time after the end of the address change detection pulse, drive the core-side and reference-side word lines to a boost voltage level higher than the power supply voltage. The sense amplifier begins comparison of the core-side and the reference-side input voltages after the second time.

Abstract: A semiconductor memory device has 2n word lines, a plurality of bit lines, a plurality of nonvolatile memory cells disposed at each intersection of the word lines and the bit lines, a write circuit for writing data to a memory cell located at an intersection of selected ones of the word lines and the bit lines, and a sense amplifier for reading data out of the memory cells. Further, the semiconductor memory device comprises a first unit for simultaneously selecting a block of 2m (n>m) word lines among the 2n word lines, and a second unit for not selecting a block of 2k (m>k) word lines among the 2m word lines. The second unit does not select the block of 2k word lines, and selects a block of 2k word lines prepared outside the 2n word lines when any one of the 2k word lines among the 2m word lines is defective. Consequently, redundant word lines are effectively employed, write and verify operations are stable, and thereby the yield and performance of the semiconductor memory device are improved.

Abstract: A semiconductor memory device has 2n word lines, a plurality of bit lines, a plurality of nonvolatile memory cells disposed at each intersection of the word lines and the bit lines, a write circuit for writing data to a memory cell located at an intersection of selected ones of the word lines and the bit lines, and a sense amplifier for reading data out of the memory cells. Further, the semiconductor memory device comprises a first unit for simultaneously selecting a block of 2m (n>m) word lines among the 2n word lines, and a second unit for not selecting a block of 2k (m>k) word lines among the 2m word lines. The second unit does not select the block of 2k word lines, and selects a block of 2k word lines prepared outside the 2n word lines when any one of the 2k word lines among the 2m word lines is defective. Consequently, redundant word lines are effectively employed, write and verify operations are stable, and thereby the yield and performance of the semiconductor memory device are improved.

Abstract: A semiconductor memory device has 2n word lines, a plurality of bit lines, a plurality of nonvolatile memory cells disposed at each intersection of the word lines and the bit lines, a write circuit for writing data to a memory cell located at an intersection of selected ones of the word lines and the bit lines, and a sense amplifier for reading data out of the memory cells. Further, the semiconductor memory device comprises a first unit for simultaneously selecting a block of 2m (n>m) word lines among the 2n word lines, and a second unit for not selecting a block of 2k (m>k) word lines among the 2m word lines. The second unit does not select the block of 2k word lines, and selects a block of 2k word lines prepared outside the 2n word lines when any one of the 2k word lines among the 2m word lines is defective. Consequently, redundant word lines are effectively employed, write and verify operations are stable, and thereby the yield and performance of the semiconductor memory device are improved.

Abstract: A semiconductor memory device has 2n word lines, a plurality of bit lines, a plurality of nonvolatile memory cells disposed at each intersection of the word lines and the bit lines, a write circuit for writing data to a memory cell located at an intersection of selected ones of the word lines and the bit lines, and a sense amplifier for reading data out of the memory cells. Further, the semiconductor memory device comprises a first unit for simultaneously selecting a block of 2m (n>m) word lines among the 2n word lines, and a second unit for not selecting a block of 2k (m>k) word lines among the 2m word lines. The second unit does not select the block of 2k word lines, and selects a block of 2k word lines prepared outside the 2n word lines when any one of the 2k word lines among the 2m word lines is defective. Consequently, redundant word lines are effectively employed, write and verify operations are stable, and thereby the yield and performance of the semiconductor memory device are improved.

Abstract: The input/output nodes of memory cells connected in series are connected to bit lines. Two of the bit lines positioned on the outsides of four successive memory cells constitute each of a plurality of bit line pairs. The bit line pairs are connected to four data lines, respectively, via switches connected to the respective bit lines. A switching control circuit turns on adjacent five of the switches. A switching circuit connects the data lines connected to the input/output nodes by the turning-on of the switches to a supply node of a first voltage, a supply node of a second voltage, and first and second sense amplifiers, respectively. Thereby, data is read from two of the memory cells simultaneously. Thus, it is possible to read data from the two memory cells simultaneously by using the simple switching control circuit without increasing the chip size.

Abstract: The input/output nodes of memory cells connected in series are connected to bit lines. Two of the bit lines positioned on the outsides of four successive memory cells constitute each of a plurality of bit line pairs. The bit line pairs are connected to four data lines, respectively, via switches connected to the respective bit lines. A switching control circuit turns on adjacent five of the switches. A switching circuit connects the data lines connected to the input/output nodes by the turning-on of the switches to a supply node of a first voltage, a supply node of a second voltage, and first and second sense amplifiers, respectively. Thereby, data is read from two of the memory cells simultaneously. Thus, it is possible to read data from the two memory cells simultaneously by using the simple switching control circuit without increasing the chip size.

Abstract: A bank selector circuit for a simultaneous operation flash memory device with a flexible bank partition architecture comprises a memory boundary option, a bank selector encoder coupled to receive a memory partition indicator signal from the memory boundary option, and a bank selector decoder coupled to receive a bank selector code from the bank selector encoder. The decoder, upon receiving a memory address, outputs a bank selector output signal to point the memory address to either a lower memory bank or an upper memory bank in the simultaneous operation flash memory device, in dependence upon the selected memory partition boundary.

Abstract: Nonvolatile semiconductor memory has a core-side cell array having word lines, bit lines and memory cells; a reference-side cell array having word lines, bit line, and reference cell; and, a sense amplifier which compares a core-side input voltage corresponding to a bit line current in the core-side cell array, and a reference-side input voltage corresponding to the bit-line current in the reference-side cell array. The core-side decoder-driver and reference-side decoder-driver drive the core-side and reference-side word lines to the power supply voltage at a first time at the end of the address change detection pulse, and, at a second time a prescribed time after the end of the address change detection pulse, drive the core-side and reference-side word lines to a boost voltage level higher than the power supply voltage. The sense amplifier begins comparison of the core-side and the reference-side input voltages after the second time.

Abstract: A semiconductor memory device has 2n word lines, a plurality of bit lines, a plurality of nonvolatile memory cells disposed at each intersection of the word lines and the bit lines, a write circuit for writing data to a memory cell located at an intersection of selected ones of the word lines and the bit lines, and a sense amplifier for reading data out of the memory cells. Further, the semiconductor memory device comprises a first unit for simultaneously selecting a block of 2m (n>m) word lines among the 2n word lines, and a second unit for not selecting a block of 2k (m>k) word lines among the 2m word lines. The second unit does not select the block of 2k word lines, and selects a block of 2k word lines prepared outside the 2n word lines when any one of the 2k word lines among the 2m word lines is defective. Consequently, redundant word lines are effectively employed, write and verify operations are stable, and thereby the yield and performance of the semiconductor memory device are improved.

Abstract: Data lines are wired next to each other. A sense amplifier receives the data and outputs an amplified signal. Dummy data lines are laid out along both sides of a data bus consisting of the data lines. The dummy data lines have the same voltage variation as the data lines during a read operation of the data stored in the memory cells. This reduces the potential differences between the data lines and the dummy data lines during a read operation. As a result, the outer data lines and the inner data lines become nearly equal to each other in coupling characteristics, and the lengths of time it takes for the data read to each of the data lines to rise become almost equal to each other. Since the data lines have smaller fluctuations in rising time, the read time (access time) is accelerated.

Abstract: The present invention discloses sector-based redundancy that is capable of making repairs using a plurality of redundant columns of memory cells in a dual bank memory device during simultaneous operation. The simultaneous operation memory device includes a plurality of redundant blocks that can be configured to be located in an upper bank or a sliding lower bank. The redundant blocks are comprised of sectors and each sector contains columns of memory cells. During simultaneous operation, the memory device is capable of reading the columns of memory cells in one bank and writing columns of memory cells in the other bank at the same time. In addition, the simultaneous operation memory device uses sector-based redundancy to repair columns of memory cells that are defective in one bank by electrically exchanging them with redundant columns of memory cells and, at the same time, repair columns of memory cells that are defective in the other bank.

Abstract: A bank selector encoder comprises a partition indicator circuit having a plurality of partition boundary indicator terminals, a plurality of inverters arranged in a plurality of columns, with each column of the inverters coupled to a respective one of a plurality of columns of ROM cells in a ROM array and a plurality of bank selector code outputs coupled to respective columns of the inverters. The partition boundary indicator terminals are capable of designating a memory partition boundary to identify an upper memory bank and a lower memory bank. The bank selector encoder is capable of generating an identifying bank selector code for each of a plurality of the predetermined memory partition boundaries. The bank selector encoder outputs code bits of a bank selector code based upon the partition boundary indicator terminals.

Abstract: An input circuit for a flash memory device is disclosed. The input circuit includes an input for receiving a voltage signal from an external source representing a digital logic signal. The input circuit further includes a pull up circuit which is coupled with the input and pulls the input to a high logic level when the input is not connected to any external source.

Abstract: A bank selector circuit for a simultaneous operation flash memory device with a flexible bank partition architecture comprises a memory boundary option, a bank selector encoder coupled to receive a memory partition indicator signal from the memory boundary option, and a bank selector decoder coupled to receive a bank selector code from the bank selector encoder. The decoder, upon receiving a memory address, outputs a bank selector output signal to point the memory address to either a lower memory bank or an upper memory bank in the simultaneous operation flash memory device, in dependence upon the selected memory partition boundary.

Abstract: A memory circuit (100) includes address circuitry (104) configured to receive address data and a plurality of I/O buffers (112). A core cell array (102) includes core cells and redundant core cells. Sense amplifiers (108) including read sense amplifiers (132) and redundant sense amplifiers may be coupled to the I/O buffers by word selection circuitry (110). Redundancy is implemented on an I/O-by-I/O basis, so that a redundant core cell and sense amplifier may be substituted for any failed bit in the core cell array.

Abstract: The reduction of electrical noise in a high voltage distribution path of a high density flash memory device is disclosed. High voltage brought on-chip from an external power source is transmitted over separate isolated voltage distribution paths to a voltage generator circuit. The voltage generator pumps up the voltage of one of the voltage paths and uses the pumped up voltage to control the distribution of the voltage from the other voltage path, whereby electrical noise from the voltage pump is isolated from the distributed voltage.