参数资料
型号: DS17487-5IND+
厂商: Maxim Integrated Products
文件页数: 20/31页
文件大小: 0K
描述: IC RTC 5V 4K NV RAM 24-EDIP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 14
类型: 时钟/日历
特点: 警报器,夏令时,闰年,NVSRAM,方波输出
存储容量: 4KB
时间格式: HH:MM:SS(12/24 小时)
数据格式: YY-MM-DD-dd
接口: 并联
电源电压: 4.5 V ~ 5.5 V
电压 - 电源,电池: 2.5 V ~ 3.7 V
工作温度: -40°C ~ 85°C
安装类型: 通孔
封装/外壳: 24-DIP 模块(0.600",15.24mm)
供应商设备封装: 24-EDIP
包装: 管件
System Maintenance Interrupt
(SMI) Recovery Stack
An SMI recovery register stack is located in the extend-
ed register bank, locations 4Eh and 4Fh. This register
stack, shown below, can be used by the BIOS to recov-
er from an SMI occurring during an RTC read or write.
The RTC address is latched on the falling edge of the
ALE signal. Each time an RTC address is latched, the
register address stack is pushed. The stack is only four
registers deep, holding the three previous RTC
addresses in addition to the current RTC address being
accessed. Figure 8 illustrates how the BIOS could
recover the RTC address when an SMI occurs.
1) The RTC address is latched.
2) An SMI is generated before an RTC read or write
occurs.
3
RTC address 0Ah is latched and the address from 1
is pushed to the “RTC Address–1” stack location.
This step is necessary to change the bank select bit,
DV0 = 1.
4) RTC address 4Eh is latched and the address from 1
is pushed to location 4Eh, “RTC Address–2” while
0Ah is pushed to the “RTC Address–1” location. The
data in this register, 4Eh, is the RTC address lost due
to the SMI.
DS17285/DS17287/DS17485/DS17487/DS17885/DS17887
Real-Time Clocks
____________________________________________________________________
27
Figure 8. ALE Waveform
RTC ADDRESS
RTC ADDRESS-1
4Eh RTC ADDRESS-2
4Fh RTC ADDRESS-3
SMI Recovery Stack
76
5432
10
DV0
AD6
AD5
AD4
AD3
AD2
AD1
AD0
REGISTER BIT DEFINITION
1
2
3
4
ALE
相关PDF资料
PDF描述
DS17487-3IND+ IC RTC 3V 4K NV RAM 24-EDIP
DS1554W-120+ IC RTC RAM Y2K 3.3V 120NS 32EDIP
MCP4132T-103E/MF IC RHEO DGTL SNGL 10K SPI 8DFN
DS1244WP-120IND+ IC NVSRAM 256KBIT 120NS 34PCM
VE-25F-MX-B1 CONVERTER MOD DC/DC 72V 75W
相关代理商/技术参数
参数描述
DS17487-5IND+ 功能描述:实时时钟 3V/5V RTC RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube
DS17487B-3 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:3V/5V Real-Time Clock
DS17487B-5 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:3V/5V Real-Time Clock
DS17487BN-3 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:3V/5V Real-Time Clock
DS17487BN-5 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:3V/5V Real-Time Clock