參數(shù)資料
型號(hào): DS17485SN-5
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: Timer or RTC
英文描述: 1 TIMER(S), REAL TIME CLOCK, PDSO24
封裝: 0.300 INCH, SOIC-24
文件頁(yè)數(shù): 20/33頁(yè)
文件大?。?/td> 410K
代理商: DS17485SN-5
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
相關(guān)PDF資料
PDF描述
DS17487-3 1 TIMER(S), REAL TIME CLOCK, PDIP24
DS17287-5 1 TIMER(S), REAL TIME CLOCK, PDIP24
DS17285-5 1 TIMER(S), REAL TIME CLOCK, PDIP24
DS17285SN-3 1 TIMER(S), REAL TIME CLOCK, PDSO24
DS17885S-3 1 TIMER(S), REAL TIME CLOCK, PDSO24
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS17485SN-5/T&R 功能描述:實(shí)時(shí)時(shí)鐘 RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時(shí)間格式:HH:MM:SS RTC 存儲(chǔ)容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube
DS17485SN-5+ 功能描述:實(shí)時(shí)時(shí)鐘 3V/5V RTC RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時(shí)間格式:HH:MM:SS RTC 存儲(chǔ)容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube
DS17486 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:3V/5V Real-Time Clock
DS17487 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:3V/5V Real-Time Clock
DS17487-3 功能描述:實(shí)時(shí)時(shí)鐘 RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時(shí)間格式:HH:MM:SS RTC 存儲(chǔ)容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube