Abstract:
A sense amplifier includes a first sensing element and a second sensing element redundant to the first sensing element. The sense amplifier further comprises a switch circuit configured to switch between the first and second sensing elements when an offset of the sense amplifier is greater than a prescribed amount.
Abstract:
A memory (12) includes a plurality of memory cells (12), a sense amplifier (18) coupled to at least one of the plurality of memory cells, a temperature dependent current generator (26) comprising a plurality of selectable temperature dependent current sources (52-62) for generating a temperature dependent current, a temperature independent current generator (28) comprising a plurality of selectable temperature independent current sources (70, 72, 74) for generating a temperature independent current, and a summer (30) coupled to the temperature dependent current generator (26) and the temperature independent current generator (28) for combining the temperature dependent current and the temperature independent current to generate a reference current for use by the sense amplifier (18). A temperature coefficient of the reference current is approximately a same as a temperature coefficient of a memory cell current of at least one of the plurality of memory cells.
Abstract:
A cell array comprises a word line and a bit line which are connected to a memory cell, and a redundant word line and a redundant bit line which are connected to a redundant memory cell. A reading section reads data held in the memory cell. A defect detecting input section receives a defect detecting signal from a test device. A dummy defect output section outputs a dummy defect signal during a predetermined period of time after the defect detecting input section receives the defect detecting signal. A data output section inverts the logic of the read data outputted from a reading circuit while the dummy defect signal is activated. This enables generation of a pseudo defect by means of a semiconductor memory without changing any test device or test program. More specifically, a single bit defect can be replaced by a predetermined bit line defect or word line defect without changing any testing environment. As a result, the efficiency of the remedy can be improved to reduce the cost of the test.
Abstract:
A memory array test and characterization capability is disclosed which allows DC characterization of the memory cells, the bit lines, and the sense amplifiers. A row decoder is provided which includes a static wordline select signal to disable self-resetting logic within the row decoder and allow the word line to remain active for a user-controlled length of time. An analog wordline drive capability allows the active wordline to be driven to a user-controllable analog level. Direct access to a pair of bitlines is provided by a multiplexer which is statically decoded to couple a pair of isolated terminals to the respective bitlines within the decoded column. This allows DC voltage levels to be impressed upon each of the two bitlines within the decoded column and/or the two bitline currents to be sensed. A separate power connection is provided for the memory array which allows operating the memory array at a different power supply voltage than the remainder of the circuit. By utilizing one or more of these features together, several tests of the memory array may be performed, including characterizing the DC transfer function of the memory cells, the standby power of the memory array, the static noise margin of the memory cells, the alpha particle susceptibility of the memory cells as a function of memory cell supply voltage, the offset voltage of bitline sense amplifiers, and others.
Abstract:
A highly suitable power conservation technique involves extending multiple word lines over a memory array row and connecting a portion of the memory cells of the memory array row to each of the word lines. Power is supplied only to the portion of the memory cells that is accessed, eliminating the static power consumption of the non-accessed memory cells. By connecting multiple word lines to select a portion of a memory row, a column address of the memory is mapped into a row decode space. Multiple metal layers in a complex integrated circuit may be exploited to form cache block select lines using multiple word lines per cell row. A storage includes a plurality of storage cells arranged in an array of rows and columns, a plurality of bit lines connecting the array of storage cells into columns, and a plurality of word lines connecting the array of storage cells into rows. The plurality of word lines include multiple word lines for a single row of the plurality of rows so that multiple portions of the storage cells in the single row are addressed by corresponding multiple word lines.
Abstract:
A circuit and method for adaptive trimming of the reference signal for sensing data during a read operation of magnetic memory cells to improve read margin for the magnetic memory cells. The circuit has a trim one-time programmable memory array programmed with offset trim data applied to magnetic memory array sense amplifiers. Sense amplifier trimming circuits receive and decode the trim data to determine offset trim signal magnitude to adjust the reference signal to improve the read margin. The method sets the offset trim level to each increment of the offset trim level. Data is written and read to the magnetic memory array, the number of errors in the array is accumulated for each setting of the offset trim level. The error levels are compared and the appropriate trim level is programmed to the trim memory cells such that a read margin of the sense amplifier is improved.
Abstract:
An example device in accordance with an aspect of the present disclosure includes a first module, a second module, and a third module. The first module is coupled to an element whose status is to be determined, and the first module is to receive an input current that increases over time. The second module is to perform a temporal derivative of a voltage across the element. The third module is to provide an output signal based on a current behavior of the element, according to a change in voltage as a function of a change in current.
Abstract:
A circuit includes a plurality of transistors responsive to a plurality of latches that store a test code. The circuit further includes a first bit line coupled to a data cell and coupled to a sense amplifier. The circuit also includes a second bit line coupled to a reference cell and coupled to the sense amplifier. A current from a set of the plurality of transistors is applied to the data cell via the first bit line. The set of the plurality of transistors is determined based on the test code. The circuit also includes a test mode reference circuit coupled to the first bit line and to the second bit line.