摘要:
A memory system that provides extra data bits without utilizing storage capacity. A first data word is fetched from memory and corrected to remove any single-bit errors. A second data word (which is a subset of the first data word as corrected) is then fetched, and new data correction bits (parity or ECC check bits) is generated for the second data word. Both the second data word and the newly-generated data correction bits are output. This structure amortizes the expense of in-system data correction over a greater data output, and over a smaller storage capacity relative to the data output.
摘要:
In a memory system comprising a plurality of memory units each of which possesses unit-level error correction capabilities and each of which are tied to a system level error correction function, memory reliability is enhanced by providing means for disabling the unit-level error correction capability, for example, in response to the occurrence of an uncorrectable error in one of the memory units. This counter-intuitive approach which disables an error correction function nonetheless enhances overall memory system reliability since it enables the employment of the complement/recomplement algorithm which depends upon the presence of reproducible errors for proper operation. Thus, chip level error correction systems, which are increasingly desirable at high packaging densities, are employed in a way which does not interfere with system level error correction methods.
摘要:
A semiconductor memory device is described in which wordline redundancy is implemented without impacting the access time. A redundant decoder circuit generates a wordline drive inhibit signal which inhibits the generation of a normal wordline signal. Deselection also deselects the normally accessed reference cells, requiring that the redundant cells provide their own reference signal. This last requirement is accomplished by utilization of twin cells for the redundant memory. Placing the redundant memory cells on the sense node side of the bit line isolators enables the effective doubling of the number of redundant cells available to each of a plurality of sub-arrays of normal memory.
摘要:
A method for fabricating an integrated circuit package or arrangement includes providing a carrier having a surface topography of projections or recesses for supporting individual semiconductor circuit chips having conversely matching bottom surface topographies to permit self-aligned positioning of the chip on the carrier. Chips are provided such that top faces of neighboring chips lie substantially in planes separated by a distance of greater than 0.0 .mu.m. The carrier is arranged and dimensioned such that the neighboring chips are separated by a gap G or spacing in a range of 1 .mu.m
摘要:
An embedded memory macro device includes a memory system and a logic circuit constructed on a common semiconductor substrate. The memory system and logic circuit communicate through a handshake procedure via a system data interlock signal. During read cycles the memory system uses the system data interlock signal to tell the logic circuit when data at memory system data outputs is valid. In the preferred embodiment, during write cycles the memory system uses the system data interlock signal to tell the logic circuit when data has been successfully written. The logic circuit needs to wait only until the system data interlock signal permits it to proceed. It then signals the memory system to reset the system data interlock signal and can immediately initiate a new read or write cycle.
摘要:
A method is provided for flash writing to multiple cells of a memory array. Initially, a first set of word lines, each of which controls connection of a memory cell of a first set of memory cells to a first bit line of a bit line pair, is turned on. The voltage between the two bit lines of the bit line pair is then equalized so that the charge on the first bit line of the bit line pair is higher than the charge on the second bit line of the bit line pair. Next, a sense amplifier attached to the bit line pair is turned on to sense a difference in charge between the bit line pair and to charge the first set of memory cells. Then a second set of word lines, each of which controls connection of a memory cell of a second set of memory cells to the second bit line is turned on. Finally, the word lines previously turned on are shut off and then the sense amplifier is shut off. Additionally, an apparatus is provided which allows for: turning on multiple word lines at one time, keeping an equalization means on until after at least one set of word lines have gone on, and controlling the operation of the sense amplifier to turn on and shut off at appropriate times.
摘要:
A DRAM having on-chip ECC and both bit and word redundancy that have been optimized to support the on-chip ECC. The bit line redundancy features a switching network that provides an any-for-any substitution for the bit lines in the associated memory array. The word line redundancy is provided in a separate array section, and has been optimized to maximize signal while reducing soft errors. The array stores data in the form of error correction words (ECWs) on each word line. A first set of data lines (formed in a zig-zag pattern to minimize unequal capacitive loading on the underlying bit lines) are coupled to read out an ECW as well as the redundant bit lines. A second set of data lines receive the ECW as corrected by bit line redundancy, and a third set of data lines receive the ECW as corrected by the word line redundancy. The third set of data lines are coupled to the ECC block, which corrects errors encountered in the ECW. The ECC circuitry is optimized to reduce the access delays introduced by carrying out on-chip error correction. The ECC block provides both the corrected data bits and the check bits to an SRAM. Thus, the check bits can be externally accessed. At the same time, having a set of interrelated bits in the SRAM compensates for whatever access delays are introduced by the ECC. To maximize the efficiency of switching from mode to mode, the modes are set as a function of received address signals.
摘要:
A CMOS integrated circuit for driving capacitance devices is provided. The circuit has an input node and an output node and includes a first transistor operatively connected to the input node which is turned "on" and "off" by the input node to supply an output signal to the output node when turned "on". A second transistor is provided, the output of which is connected to the output node when turned "on" to supply an output signal thereto. A control circuit is provided to turn on the first transistor prior to the second transistor, and to turn on the second transistor if and only if the slew rate of the output signal of the first transistor is less or slower than a given value. With this arrangement, if there is a low total capacitance of the capacitance devices being driven, the first transistor will have a fast enough slew rate that it will perform the entire charging function of the devices without turning on the second transistor; however, if the total capacitance of the devices being charged is sufficiently large, the low slew rate of the first transistor will cause the second transistor to be turned on, thereby providing additional charging voltage to the capacitance devices, thus decreasing the time that would be required if only the first transistor were employed for the entire charging.
摘要:
This invention relates to semiconductor memories and includes a sense amplifier architecture in which sensed data bit or column lines are electrically isolated and shielded from their immediately adjacent active neighbors by utilization of non-selected bit lines as an AC ground bus. In its simplest embodiment, shielded bit line (SBL) architecture includes two pairs of opposed bit lines associated with a common sense amplifier. One of each of the bit line pairs is multiplexed into the sense amplifier and the other unselected bit line pair is clamped to AC ground to shield the selected bit line pair from all dynamic line-to-line coupling.
摘要:
Large area chip functionality is tested at an intermediate level in the manufacturing process. A process sequence is implemented in which a layer of insulator material is deposited over the chip. This layer is then processed to selectively open areas over existing vias which are to be used for chip level testing. The other vias remain covered with insulator. A sacrificial metal level is then deposited on the insulator layer and patterned to create adequately large test pad areas connected to exposed vias. This metal layer and the insulator layer covering the other buried vias are removed after testing to re-establish the full via set. As an extension to this basic test process, test circuits can be formed around or beside the chip to be tested in the kerf areas separating the chip from other chips on the semiconductor wafer. Connections to the test circuits is with a sacrificial metal layer over an insulator layer. The sacrificial metal layer and insulator layer are removed after testing. The test circuits are scribed off in the process of separating the chips after back end of line processing is completed.