摘要:
A memory cell array ARY includes a plurality of sub-arrays SARY. A data transfer unit DTU alternately accesses the sub-arrays SARY to transfer data between the sub-arrays SARY. Accordingly, it is possible to transfer data stored in one of the sub-arrays SARY to another sub-array SARY without outputting the data to a bus connected to a semiconductor memory MEM. For example, a microcontroller CNT in a system MSYS can use the bus during the data transfer since the bus is not used for the data transfer. As a result, it is possible to prevent the performance of the system MSYS from being deteriorated due to the data transfer.
摘要:
A memory controller multiplexes access signals each consisting of a plurality of bits as optical signals and outputs the multiplexed optical signals. At this time, the optical signals whose wavelengths differ depending on memory devices are generated. A memory interface unit demultiplexes the multiplexed optical signals into the original optical signals and converts the demultiplexed optical signals into electrical signals. The memory interface unit determines to which of the memory devices the electrical signals resulting from the conversion should be outputted, according to the wavelengths of the demultiplexed optical signals. This frees the memory controller from a need for transmitting to the memory interface unit a signal for identifying the memory device. The memory interface unit need not include a decoding circuit for identifying the memory device.
摘要:
A memory controller converts controller output signals output from a controller int memory input signals according to the operation specifications of memory chips to operate, and outputs the resultant to the memory chips through a common bus. The memory controller also receives memory output signals output from the memory chips through the common bus, and converts the received signals into controller input signals receivable to the controller. This allows the single memory controller to access the plurality of types of memory chips. As a result, the memory controller can be reduced in chip size, lowering the cost of the memory system.
摘要:
A memory controller converts controller output signals output from a controller into memory input signals according to the operation specifications of memory chips to operate, and outputs the resultant to the memory chips through a common bus. The memory controller also receives memory output signals output from the memory chips through the common bus, and converts the received signals into controller input signals receivable to the controller. This allows the single memory controller to access the plurality of types of memory chips. As a result, the memory controller can be reduced in chip size, lowering the cost of the memory system.
摘要:
A semiconductor memory device includes a memory part which stores data, a decoder which decodes a command externally supplied to the semiconductor memory device, and a precharge protection circuit which dynamically determines, based on the command decoded by the decoder, a period necessary to precharge a predetermined circuit part of the semiconductor memory device, so that a precharge operation on the predetermined circuit part can be protected.
摘要:
A DRAM (dynamic Random Access Memory) having a plurality of memory cells includes a data read/write circuit reading or writing data for the memory cells, a self-refresh circuit refreshing data stored in the memory cells, and a power supply unit for supplying electric power to the data read/write circuit and the self-refresh circuit, the electric power having a first voltage level in a normal operation mode and a second voltage level in a self-refresh mode, wherein the second voltage level is lower than the first voltage level.
摘要:
A semiconductor memory has a plurality of bit lines, a plurality of word lines, a plurality of memory cells, a power source unit, and a plurality of sense amplifiers. The memory cells are formed at intersection portions of the bit lines and the word lines, and each of the memory cells includes a transistor and a capacitor. The power source unit is connected to the capacitors of the memory cells. Each of the sense amplifiers, which is connected to a corresponding one of the bit lines and the power source, is used to amplify a voltage between a potential of the corresponding bit line. This memory realizes high integration, large capacity, and low power consumption.
摘要:
A memory and a method for reading out of memory including a register for holding one row of data of a memory cell array, a plurality of first switching transistors for switching ON/OFF between a plurality of bit lines and the corresponding bits in the register, a plurality of second switching transistors for switching ON/OFF between the bit lines and a pair of data bus lines and a plurality of third switching transistors for switching ON/OFF between the data bus lines and the bits in the register. In random access of memory cells, selection and control is performed for the plurality of second switching transistors with an output of a column decoder. In sequential reading out of the register, one row data of the memory cells selected by a row decoder are written in the register by controlling the plurality of first switching transistors and with an output of the column decoder, sequential selection and control of the plurality of third switching transistors is performed.
摘要:
A semiconductor memory device has an oscillator unit for generating refresh pulses, a refresh address detection unit for detecting refreshed addresses and outputting a predetermined signal upon the completion of the refreshing of all addresses, and an output control unit for continuing a self-refresh mode to refresh all addresses according to the signal from the refresh address detection unit, before releasing the self-refresh mode in response to an external signal. Therefore, the refresh operation is continued until all cells are refreshed, thereby data stored in the semiconductor memory device is not lost and is correctly refreshed.
摘要:
A semiconductor memory device including a plurality of word lines and a plurality of bit lines; a plurality of memory cells connected between one of the word lines and one of the bit lines, at least one of the memory cells connected to the word lines being of a first type having an N channel type transfer gate transistor, at least one of the memory cells connected to the word lines being of a second type having a P channel type transfer gate transistor; and means for applying a selection signal to a selected word line, the selection signal having one of two opposite polarities in accordance with an access to the first type memory cells and an access to the second type memory cells.