3BHE014071P201卡件控制器,ABB产品尺寸
实时时钟/NVRAM/计时器功能MVME2700采用SGS Thomson表面安装M48T59RAM和时钟芯片，提供8KB的非易失性静态RAM、实时时钟和看门狗定时器功能。这个芯片提供时钟，振荡器、晶体、电源故障检测、内存写保护、8KBNVRAM和一个由两部分组成的包装中的电池：
❏ 包含实时时钟的28针330mil SO设备振荡器，电源故障检测电路，定时器逻辑
3BHE014071P201卡件控制器8KB静态RAM和电池的镀金插座❏ SNAPHAT®电池包含一个晶体和电池SNAPHAT电池组安装在M48T559的顶部装置电池外壳带有键，以防止反向插入。时钟提供秒、分、时、日、日、月和年BCD 24小时格式。28、29（闰年）和30天的修正月份是自动生成的。时钟不会产生中断。虽然M48T559是一个8位设备，但从支持连接至M48T559的ISA总线。参考MVME2600/2700
系列程序员参考指南和M48T559数据表详细的编程和电池寿命信息。关于电池实时时钟的电源是M4T28-BR12 SH1锂电池电池采用插座，便于拆卸和更换。电池在55°C下的储存寿命为50年。其使用寿命寿命在很大程度上取决于电路板的环境温度和通电占空比。70°C时，电池的预期时间跨度保护（100%工作周期）为10年。在较低的环境温度下，备份时间相应更长。
如果您打算将电路板放入存储器，则通过停止振荡器将M48T559置于省电模式将延长电路板的使用寿命电池这在高环境温度下尤为重要。进入在省电模式下，执行PPCBug PS命令。请参阅调试器第5-4页上的命令或其等效的应用程序特定命令。将电路板恢复使用时，执行PPCBug SET命令（设置mmddyyhhmm）在安装后重新启动振荡器并初始化时钟。锂电池包含易燃材料，如锂和有机溶剂。如果锂电池受到虐待或处理不当，它们可能爆裂并点燃，可能导致受伤和/或火灾。在处理锂电池时，请仔细遵循列出的注意事项为了防止事故发生。
Real-Time Clock/NVRAM/Timer Function
The MVME2700 employs an SGS-Thomson surface-mount M48T59
RAM and clock chip to provide 8KB of nonvolatile static RAM, a realtime clock, and a watchdog timer function. This chip supplies a clock,
oscillator, crystal, power failure detection, memory write protection, 8KB
of NVRAM, and a battery in a package consisting of two parts:
❏ A 28-pin 330mil SO device containing the real-time clock, the
oscillator, power failure detection circuitry, timer logic, 8KB of
static RAM, and gold-plated sockets for a battery
❏ A SNAPHAT® battery housing a crystal along with the battery
The SNAPHAT battery package is mounted on top of the M48T559
device. The battery housing is keyed to prevent reverse insertion.
The clock furnishes seconds, minutes, hours, day, date, month, and year in
BCD 24-hour format. Corrections for 28-, 29- (leap year), and 30-day
months are made automatically. The clock generates no interrupts.
Although the M48T559 is an 8-bit device, 8-, 16-, and 32-bit accesses from
the ISA bus to the M48T559 are supported. Refer to the MVME2600/2700
Series Programmer’s Reference Guide and to the M48T559 data sheet for
detailed programming and battery life information.
About the Battery
The power source for the real-time clock is an M4T28-BR12 SH1 lithium
battery which is socketed for easy removal and replacement.
The battery has a storage life of 50 years at 55° C. The length of its service
lifetime is very dependent on the ambient temperature of the board and the
power-on duty cycle. At 70° C, the anticipated time span for battery
protection (100% duty cycle) is 10 years. At lower ambient temperatures,
the backup time is correspondingly longer.
If you intend to place the board in storage, putting the M48T559 in powersave mode by stopping the oscillator will extend the service life of the
battery. This is especially important at high ambient temperatures. To enter
power-save mode, execute the PPCBug PS command. Refer to Debugger
Commands on page 5-4 or its equivalent application-specific command.When restoring the board to service, execute the PPCBug SET command
(set mmddyyhhmm) after installation to restart the oscillator and initialize
the clock.
!
Warning
Lithium batteries incorporate flammable materials such as lithium and
organic solvents. If lithium batteries are mistreated or handled incorrectly,
they may burst open and ignite, possible resulting in injury and/or fire.
When dealing with lithium batteries, carefully follow the precautions listed
below in order to prevent accidents.
