| 摘要 |
<p>PURPOSE: To accelerate a writing operation, to simplify control and to reduce a price of the semiconductor memory device that uses a flash memory with built-in data buffer. CONSTITUTION: This device is provided with a medium 15 composed of a flash memory chip 1 provided with a data buffer 2 such as DRAM or SRAM inside a batch erasure type EEPROM, data control circuit 14 for controlling the exchange of data with a host, power source part 10, and backup power source 12 for selectively supplying backup power to the medium 15. When writing to the data buffer 2 inside the flash memory chip 1 is completed, a microprocessor 8 of the data control circuit 14 reports the completion of writing to the host and executes data writing from the data buffer 2 to the batch erasure type EEPROM independently of the data control circuit 14 inside the flash memory chip 1. The data writing from the data buffer 2 to the batch erasure type EEPROM is guaranteed by the backup power source 12 even at the time of power failure.</p> |
