參數(shù)資料
型號: DS17487B-5
英文描述: 3V/5V Real-Time Clock
中文描述: 3V/5V實時時鐘
文件頁數(shù): 23/38頁
文件大小: 427K
代理商: DS17487B-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
DS17487BN-3 3V/5V Real-Time Clock
DS17487BN-5 3V/5V Real-Time Clock
DS17487N-3 3V/5V Real-Time Clock
DS17487N-5 49.9 1% 1/4W 1206
DS17486 3V/5V Real-Time Clock
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS17487BN-3 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:3V/5V Real-Time Clock
DS17487BN-5 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:3V/5V Real-Time Clock
DS17487N-3 功能描述:IC RTC 3V 4K NV RAM 24-EDIP RoHS:否 類別:集成電路 (IC) >> 時鐘/計時 - 實時時鐘 系列:- 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:- 類型:時鐘/日歷 特點:警報器,閏年,SRAM 存儲容量:- 時間格式:HH:MM:SS(12/24 小時) 數(shù)據(jù)格式:YY-MM-DD-dd 接口:SPI 電源電壓:2 V ~ 5.5 V 電壓 - 電源,電池:- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-WDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:8-TDFN EP 包裝:管件
DS17487N-5 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:3V/5V Real-Time Clock
DS17488 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:3V/5V Real-Time Clock