Abstract: A power-up initialization circuit includes a delay chain circuit and a signal generator circuit. The delay chain circuit receives a power supply voltage, and applies a predetermined delay amount to the power supply voltage for generating a delayed output voltage. The signal generator circuit receives the delayed output voltage from the delay chain circuit, and generates and outputs at least one power-up initialization signal in response to the delayed output voltage.

Abstract: A novel scheme for screening weak memory cell includes a cell coupled to a leakage stress delivery circuitry (LSDC), which, in turn, is coupled to an induced leakage adjustment control (ILAC). The LSDC includes a combination of PMOS transistors, NMOS transistors or both PMOS and NMOS transistors that are controlled by a plurality of stress inducing signals. The PMOS and/or NMOS transistors of the LSDC are coupled to a pair of complementary data lines. The complementary data lines are inputs to a sense amplifier and are outputs of a write driver. The ILAC controls the quantity of the leakage stress applied through the LSDC to the pair of complementary data lines. The ILAC further includes a leakage varying circuitry that is configured to adjust the leakage stress applied to the complementary data lines through the LSDC.

Abstract: An apparatus and method for minimizing the access time incurred when accessing redundant columns of a dynamic random access memory (DRAM) is herein disclosed. A pair of redundant columns is associated with a defective column. Each pair of redundant columns has a single redundant column decoder that provides access to the column data in the pair of redundant columns. The redundant column decoder is enabled by the column repair circuitry when it receives a column address signal indicating that a defective cell is to be accessed. When a defective column is accessed, the column data from the pair of associated redundant columns is read onto the IO lines as well as the data from the defective column. The three voltages are combined forming an IO signal and the complements of the three voltages are combined forming an IO-BAR signal. The sense amplifier determines the column data value based on the differential between the IO and IO-BAR signals.

Abstract: A multibank DRAM memory is described having individual row address strobe bar (RASB) and column address strobe bar (CASB) signals. Logically, only one row can be activated in each memory bank at a time and column access can be performed on one memory bank at a time. A token state machine is used to coordinate column access. In a first embodiment, two banks are utilized having respective asynchronous RASB signals transmitted from an external source. In a second embodiment, N DRAM memory banks are utilized having respective asynchronous internal RASB (IRASB) and internal CASB (ICASB) signals. A global RASB signal and a RASB identifier signal (RID) is used to generate the N IRASB and ICASB signals. The RID signal identifies a particular IRASB signal that is to be generated. The token state machine is operated in a round robin manner. In a third embodiment, the N DRAM memory banks are operated in a synchronous manner.

Abstract: The Vpp generator for use in a dynamic random access memory has a pump circuit and a voltage regulator. The voltage regulator controls the pump circuit such that the pumped up voltage has a maximum predetermined value. The prior art Vpp regulator sets the pumped up voltage, Vpp, to approximately a supply voltage, Vcc, plus the threshold voltage of a memory cell access transistor. This level becomes very high when the supply voltage, Vcc, is high and may overstress the devices. The present invention regulates the pumped up voltage, Vpp, at a substantially constant voltage level for high supply voltages. This level is safe and will not cause overstress.

Abstract: A dynamic random access memory includes memory cells located at intersections of word lines and differential bit line pairs. A row decoder activates a word line in response to a row address. A first sense amplifier coupled to each bit line pair then increases the small differential voltage of the bit line pair to positive and negative power supply voltages. The first sense amplifier is then isolated from the bit lines so that the bit lines may be equalized. The contents of memory cells along the activated word line are stored in corresponding first sense amplifiers, and the memory functions as a by-one static random access memory during successive page-mode cycles. At the end of the page-mode cycles, the first sense amplifiers are recoupled to the bit lines, and second sense amplifiers update modified data and refresh the charge stored in the memory cells.