參數(shù)資料
型號: DS17485SN-5
英文描述: 3V/5V Real-Time Clock
中文描述: 3V/5V實(shí)時(shí)時(shí)鐘
文件頁數(shù): 23/38頁
文件大小: 427K
代理商: DS17485SN-5
DS17485/DS17487
23 of 38
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.
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.
相關(guān)PDF資料
PDF描述
DS17487 3V/5V Real-Time Clock
DS17487-3 3V/5V Real-Time Clock
DS17487-5 3V/5V Real-Time Clock
DS17487B-3 3V/5V Real-Time Clock
DS17487B-5 3V/5V Real-Time Clock
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