Abstract: A test method includes providing an integrated circuit, where the integrated circuit includes a memory base cell, where the memory base cell includes a first storage node set, a second storage node set, a set of other nodes, and a set of circuit elements each having a plurality of terminals, where the set of other nodes includes a first data node for accessing the first storage node set, a first access control node for controlling the access of the first storage node set, a first supply node for supplying the first storage node set, and a second supply node for supplying the second storage node set, where the first and second supply nodes are of the same sinking or sourcing type.

Abstract: A set of memory cell test structures and a method for assessing of the static noise margin (SNM) of a memory cell or cells, using discrete point measurement structures provided either on-chip or within the scribe lines. A set of memory structures may comprise first and second test structures, individually comprising a memory cell, having one or more left and right half-bit test structures having hard-wired connections between select nodes of each memory cell half-bit and one or more voltage supplies. The half-bits of the first test structure are configured for measuring respective left and right standby SNM values, and the half-bits of the second test structure are configured for measuring respective left and right cell ratio values at respective output nodes of the structures, using applied supply voltages for on-chip assessment of the static noise margin of the memory cells.

Abstract: A set of memory cell test structures and a method are disclosed for assessment of the static noise margin (SNM) of a memory cell or an array of such cells, for example, of SRAM cells of an integrated circuit device, using discrete point measurement structures provided either on-chip or within the scribe lines. In one embodiment, the set of memory structures comprises first and second test structures, individually comprising a memory cell, having one or more left and right half-bit test structures having hard-wired connections between select nodes of each memory cell half-bit and one or more voltage supplies. The half-bits of the first test structure are configured for measuring respective left and right standby SNM values, and the half-bits of the second test structure are configured for measuring respective left and right cell ratio values at respective output nodes of the structures, using applied supply voltages for on-chip assessment of the static noise margin of the memory cells.

Abstract: A method (200) for determining various bit failure modes in a static random access memory device. A hard/soft bit failure test sequence is performed on each cell of the memory device to determine whether the cell exhibits a hard bit failure or a soft bit failure, then a data retention test is performed on the cell having soft bit failure to determine whether the cell exhibits a data retention failure. A write or disturb test sequence is then performed on the cell not having data retention failure, and a read or disturb test sequence is performed on the cell having write or disturb failure. Finally, a disturb test sequence is performed on the cell having read or disturb failure, and then an analysis is performed on the data from the tests to determine whether the cell exhibits one of a write, read, or disturb failure.

Abstract: Methods (400, 500, and 600) are disclosed for testing a memory device by tailoring an algorithm (460) used in the testing based on the preferred or intrinsic data state 425 that is obtained upon power-up of an advanced technology SRAM memory device (100). The methods (400, 500, and 600) take advantage of the observation that such SRAM devices repeatedly power-up in a preferred state 310. Accordingly, one method 500 comprises powering-up 510 the memory device and reading 520 a preferred power-up data state of each cell of the memory device without memory initialization or writes. The method 500 then captures and stores 530 a data state associated with the preferred power-up data state of each cell 100 and utilizes the stored power-up data state 310 or an inverse of the power-up data state 320 to tailor 540 a test pattern used by the test algorithm 460.

Abstract: A temperature dependent clock circuit (100) is disclosed. The clock circuit (100) includes a reference circuit (102) that provides a first group of reference signals (108) with positive temperature coefficients and a second group of reference signals (110) with negative temperature coefficients. A sample circuit (104) compares the first group of signals (108) with a second group of signals (110) and provides a group of bias signals (112) representative of the operating temperature of the clock circuit (100). A frequency controllable oscillator circuit (106) provides an output clock signal (CLK) having a frequency that is dependent upon the values of the bias signals (112).

Abstract: A plurality of substrate bias circuits (14, 16, and 18) are designed to provide a stable substrate reference potential for a variety of operating modes. Only one of the bias circuits is enabled by a control circuit (12) at any time for any operational mode. An on-demand boost bias circuit (16) is enabled whenever a level detector (20) indicates substrate bias has exceeded a predetermined limit during special operating modes such as burn-in or parallel test.

Abstract: A read-only memory (ROM) embedded mask release number for a built-in self-test of a memory device is provided. A synchronous dynamic random access memory (10) comprises a conventional memory (12) and a built-in self-test arrangement (14). The built-in self-test arrangement (14) includes a read only memory (ROM) (72) which stores a plurality of algorithms. Each algorithm is comprised of a series of array access instructions (140) and program access instructions (142). The last instruction in ROM (72) is an idle instruction (120). Associated with idle instruction (120) is an identification number (132). Once stored in ROM (72), the identification number (132) can be read without the use of additional equipment.

Abstract: A circuit and method for providing a plurality of voltage regulators whose outputs are constant for ranges of different external voltages are disclosed. The voltage regulators are made to be adaptable to two different ranges of external voltages through use of a master-slice technique. Furthermore, in a first voltage regulator, the supply current capability of the regulator is significantly increased under very low external voltage conditions. In a second voltage regulator, the voltage level on any node of the regulator does not exceed a voltage level that is too high, yet still sinks most of its current from the external power supply. A third voltage regulator is able to charge and discharge its output voltage so that it will maintain at a constant level. Finally, a fourth voltage regulator is optimized to reduce dielectric leakage.