参数资料
型号: DS1685S-5
厂商: DALLAS SEMICONDUCTOR
元件分类: Timer or RTC
英文描述: 1 TIMER(S), REAL TIME CLOCK, PDSO24
封装: SOIC-24
文件页数: 16/39页
文件大小: 290K
代理商: DS1685S-5
DS1685/DS1687
23 of 39
SYSTEM MAINTENANCE INTERRUPT (SMI) RECOVERY STACK
An SMI recovery register stack is located in the extended register bank, locations 4Eh and 4Fh. This
register stack, shown below, can be used by the BIOS to recover from an SMI occurring during an RTC
read or write.
RTC ADDRESS
RTC ADDRESS-1
4Eh
RTC ADDRESS-2
4Fh
RTC ADDRESS-3
SMI RECOVERY STACK
76
54
3
2
1
0
DV0
AD6
AD5
AD4
AD3
AD2
AD1
AD0
REGISTER BIT DEFINITION
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. The following waveform 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.
1
2
3
4
ALE
相关PDF资料
PDF描述
DS1685EN-3 1 TIMER(S), REAL TIME CLOCK, PDSO24
DS1685E-3 1 TIMER(S), REAL TIME CLOCK, PDSO24
DS1685EN-5 1 TIMER(S), REAL TIME CLOCK, PDSO24
DS1685-5 1 TIMER(S), REAL TIME CLOCK, PDIP24
DS1685SN-3 1 TIMER(S), REAL TIME CLOCK, PDSO24
相关代理商/技术参数
参数描述
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DS1685S-5/TR 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:3V/5V Real-Time Clocks
DS1685S-5_12 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:3V/5V Real-Time Clocks
DS1685S-5+ 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
DS1685S-5+T& 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:3V/5V Real-Time Clocks