| 摘要 |
PURPOSE:To detect abnormal voltage, control write/read out, and to allow information of the abnormality of a memory action by providing a voltage detection means every package to be constructed by a CMOS-SRAM. CONSTITUTION:A supply voltage VCC, HOLD input terminal is provided with a voltage detection function consisting of R1-R3 as well as an operational amplifier 2, and sends out a low voltage detection signal ''1'' when the VCC, HOLD to an MEM10 consisting of a CMOS-SRAM becomes below the preset threshold values. This detection signal controls the action of respective row decoders 12 and column decoder 13 through an AND gate 17a, performs an interrupting action by a tri-state buffer 16a, and releases an output despite the exsistence of a data input. Therefore, a memory control function to receive errors suspends access and informs an operator by displaying. |
