Abstract:
One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
Abstract:
When detected number of errors data Nerror exceeds the upper limit number of errors Nmax, an error correction circuit of a memory controller stores twice as long data length as stored data length for execution Sdata as the data length for execution Sdata in a correction information memory unit, and code length Scref longer than the data length for execution Sdata and detectable more errors than the upper limit number of errors as the code length for execution Scode in the correction information memory unit 32 (step S100 and S110). The error correction circuit encodes input data using BCH code having the stored code length for execution Scode, stored encoded data in a semiconductor memory device, is input data stored in the semiconductor memory device, performs error correction for input data using BCH code, and decode error corrected data.
Abstract:
When write data D is high rewritten data, a PC 10 controls a DRAM 24 to store the write data D (steps S100 and S110). When the write data D is not the high rewritten data, the PC 10 outputs an RRAM write request signal and the write data D to an SSD (step S100 and S120). A memory controller of the SSD input the RRAM write request signal controls the RRAM and an SRAM to store the write data D in the RRAM or the SRAM. This treatment enables data stored in the DRAM to be rewritten frequently. Therefore, the decrease of number of times of refresh operation of the DRAM and the decrease of power consumption are accomplished.
Abstract:
A semiconductor memory device capable of preventing a defect caused by lowering the etching precision in an end area of the memory cell array is provided. A first block is constructed by first memory cell units each having of memory cells, a second block is constructed by second memory cell units each having a plurality of memory cells, and the memory cell array is constructed by arranging the first blocks on both end portions thereof and arranging the second blocks on other portions thereof. The structure of the first memory cell unit on the end side of the memory cell array is different from that of the second memory cell unit. Wirings for connecting the selection gate lines of the memory cell array to corresponding transistors in a row decoder are formed of wiring layers formed above wirings for connecting control gate lines of the memory cell array to the transistors in the row decoder.
Abstract:
One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
Abstract:
One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
Abstract:
A NAND cell unit includes memory cells which are connected in series. An erase operation is effected on all memory cells. Then, a soft-program voltage, which is opposite in polarity to the erase voltage applied in an erase operation, is applied to all memory cells, thereby setting all memory cells out of an over-erased state. Thereafter, a program voltage of 20V is applied to the control gate of a selected memory cell, 0V is applied to the control gates of the two memory cells provided adjacent to the selected memory cell, and 11V is applied to the control gates of the remaining memory cells. Data is thereby programmed into the selected memory cell. The time for which the program voltage is applied to the selected memory cell is adjusted in accordance with the data to be programmed into the selected memory cell. Hence, data “0” can be correctly programmed into the selected memory cell, multi-value data can be read from any selected memory cell at high speed.
Abstract:
A semiconductor device of this invention includes a first circuit for initializing a predetermined circuit in accordance with the level of a power source voltage, a second circuit for controlling the output from the first circuit by activation or deactivation, and an activation control circuit for activating or deactivating the second circuit in accordance with external input.
Abstract:
One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
Abstract:
A non-volatile semiconductor device has a memory cell array having electrically erasable programmable non-volatile memory cells, reprogramming and retrieval circuits that temporarily store data to be programmed in the memory cell array and sense data retrieved from the memory cell array. Each reprogramming and retrieval circuit has first and second latches that are selectively connected to the memory cell array and transfer data. A controller controls the reprogramming and retrieval circuits on a data-reprogramming operation to and a data-retrieval operation from the memory cell array. Each reprogramming and retrieval circuit has a multilevel logical operation mode and a caching operation mode. In the multilevel logical operation mode, re-programming and retrieval of upper and lower bits of two-bit four-level data is performed using the first and the second latches to store the two-bit four-level data in one of the memory cells in a predetermined threshold level range. In the caching operation mode, data transfer between one of the memory cells selected in accordance with a first address and the first latch is performed while data transfer is performed between the second latch and input/output terminals in accordance with a second address with respect to one-bit two-level data to be stored in one of the memory cells.