Renesas Electronics Corporation

Nec Electronics Corporation

Youji Terauchi

Takao Kondo

Yuuji Kuge

When data erasure of a flash memory is interrupted and restarted from the interrupted point, time required for the data erasure is shortened. A flash memory includes a memory cell(s), a verification circuit, and a power supply circuit. The verification circuit measures a threshold voltage of the memory cell(s) by verifying an erasure state of the memory cell(s). The power supply circuit applies, to the memory cell(s), one or more pulse voltages whose initial pulse voltage has a strength that corresponds to the measured threshold voltage.

Flash memory and data erasing method of the same

A memory control circuit includes a conversion circuit performing a conversion processing for parallel readout bit data formed from individual bits read out from memory cells of a nonvolatile memory, by setting the individual bit that is once again read out from the memory cell, which is previously determined to be successfully storing an expectation value, to a corresponding expectation value expected to be stored in the memory cell, and a determination circuit determining a result of a write processing to write parallel expectation value data to the nonvolatile memory, based on the parallel readout bit data converted by the conversion circuit and the parallel expectation value data.

Memory control circuit, semiconductor integrated circuit, and verification method of nonvolatile memory

A flash memory includes a data area in which first and second k-bit data (k is a natural number) are stored; and an additional data area in which a first additional m-bit data (m is a natural number) and a second additional m-bit data used to respectively identify the first and second data are stored. The first additional data and the second additional data have different values.

Flash memory, memory control circuit, microcomputer and memory control method

A memory control circuit according to an embodiment of the present invention includes: a writable/readable memory; a comparison unit comparing write data to write in the memory with read data that is read from a memory address where the write data is written; a comparison result storage unit storing a comparison result compared by the comparison unit in association with the memory address; and a control unit controlling retry processing of rewriting the write data to the memory address determined to be unverified based on the stored comparison result.

Memory control circuit, microcomputer, and data rewriting method

A testing circuit includes m block test units and a first logical processing unit. The block test unit compares a first data outputted from a test object with a reference data, and outputs a result as a test circuit output signal based on a output control signal. The first logical processing unit judges whether the all of the m test circuit output signals indicate that the first data is coincident with the reference data, and outputs a result as a total judgment result signal based on the m test circuit output signals. The block test unit includes a block judging unit and a block output selecting unit. The block judging unit compares the first data with the reference data to judge whether the first data is coincident with the reference data, and outputs a result as a block judgment result signal.

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Kanagawa, Japan

Youji Terauchi