Patent Number: 7,085,946

Title: Backup memory control unit with reduced current consumption having normal self-refresh and unsettled modes of operation

Abstract: A backup memory control unit can reduce the current consumption when a memory (SDRAM) is inactive by providing the memory with an unsettled mode in which no power is supplied to the memory. It provides the memory with the unsettled mode, and halts the power supply from a backup power supply to the SDRAM in the unsettled mode in which the SDRAM is not in operation, thereby limiting an increase in the current consumption. The functions are executed by a hardware circuit without using a backup microcomputer.

Inventors: Yokoyama; Chikara (Hyogo, JP), Higasa; Kyoji (Tokyo, JP), Ohtsuka; Kazuyoshi (Tokyo, JP)

Assignee: Mitsubishi Denki Kabushiki Kaisha

International Classification: G06F 1/28 (20060101); G06F 1/30 (20060101); G06F 1/32 (20060101); G11C 5/14 (20060101)

Expiration Date: 8/01/02018