DS1642中文资料非易失时钟RAM数据手册ADI规格书

描述 Description

The DS1642 is a 2k x 8 nonvolatile static RAM and a full-function real-time clock (RTC), both of which are accessible in a bytewide format. The nonvolatile time keeping RAM is pin and function equivalent to any JEDEC-standard 2k x 8 SRAM. The device can also be easily substituted in ROM, EPROM, and EEPROM sockets, providing read/write nonvolatility and the addition of the real-time clock function. The real-time clock information resides in the eight uppermost RAM locations. The RTC registers contain year, month, date, day, hours, minutes, and seconds data in 24-hour BCD format. Corrections for the day of the month and leap year are made automatically. The RTC clock registers are double-buffered to avoid access of incorrect data that can occur during clock update cycles. The double-buffered system also prevents time loss as the timekeeping countdown continues unabated by access to time register data. The DS1642 also contains its own power-fail circuitry, which deselects the device when the VCC supply is in an out-of-tolerance condition. This feature prevents loss of data from unpredictable system operation brought on by low VCC as errant access and update cycles are avoided.

特性 Features

• Integrated NV SRAM, Real-Time Clock, Crystal, Power-Fail Control Circuit, and Lithium Energy Source
• Standard JEDEC Bytewide 2k x 8 Static RAM Pinout
• Clock Registers are Accessed Identically to the Static RAM. These Registers are Resident in the Eight Top RAM Locations
• Totally Nonvolatile with Over 10 Years of Operation in the Absence of Power
• Access Times of 85ns and 100ns
• Quartz Accuracy ±1 Minute a Month at +25°C, Factory Calibrated
• BCD-Coded Year, Month, Date, Day, Hours, Minutes, and Seconds with Leap Year Compensation Valid Up to 2100
• Power-Fail Write Protection Allows for ±10% VCC Power Supply Tolerance
• Lithium Energy Source is Electrically Disconnected to Retain Freshness Until Power is Applied for the First Time

简介

DS1642属于集成电路（IC）的实时时钟。由制造生产的DS1642实时时钟实时时钟 (RTC) 为几乎所有需要保持精确时间的电子设备提供时间和/或日期信息。时钟类型有二进制计数器、时钟/日历/监控器、历时计时器、幻时钟芯片、便携式系统控制器、温度记录器、时间事件记录器和计时器时钟外设。其包含 2 B 至 2 MB 不等的存储器，接口选项有 I2C、并行、串行、SPI、1 线式、2 线式、3 线式和 4 线式。