參數(shù)資料
型號(hào): DS1642-100
廠商: DALLAS SEMICONDUCTOR
元件分類: Timer or RTC
英文描述: 0 TIMER(S), REAL TIME CLOCK, PDIP24
文件頁(yè)數(shù): 4/11頁(yè)
文件大小: 138K
代理商: DS1642-100
DS1642
2 of 11
prevents time loss as the timekeeping countdown continues unabated by access to time register data. The
DS1642 also contains its own power-fail circuitry which deselects the device when the VCC supply is in
an out-of-tolerance condition. This feature prevents loss of data from unpredictable system operation
brought on by low VCC as errant access and update cycles are avoided.
CLOCK OPERATIONS-READING THE CLOCK
While the double-buffered register structure reduces the chance of reading incorrect data, internal updates
to the DS1642 clock registers should be halted before clock data is read to prevent reading of data in
transition. However, halting the internal clock register updating process does not affect clock accuracy.
Updating is halted when a 1 is written into the read bit, the 7th most significant bit in the control register.
As long as a 1 remains in that position, updating is halted. After a halt is issued, the registers reflect the
count, that is day, date, and time that was current at the moment the halt command was issued. However,
the internal clock registers of the double-buffered system continue to update so that the clock accuracy is
not affected by the access of data. All of the DS1642 registers are updated simultaneously after the clock
status is reset. Updating is within a second after the read bit is written to 0.
DS1642 BLOCK DIAGRAM Figure 1
DS1642 TRUTH TABLE Table 1
VCC
CE
OE
WE
MODE
DQ
POWER
VIH
X
DESELECT
HIGH Z
STANDBY
VIL
X
VIL
WRITE
DATA IN
ACTIVE
VIL
VIH
READ
DATA OUT
ACTIVE
5 VOLTS ± 10%
VIL
VIH
READ
HIGH Z
ACTIVE
<4.5 VOLTS >VBAT
X
DESELECT
HIGH Z
CMOS STANDBY
<VBAT
X
DESELECT
HIGH Z
DATA RETENTION
MODE
相關(guān)PDF資料
PDF描述
DS1642-70 REAL TIME CLOCK, PDMA24
DS1643-100 1 TIMER(S), REAL TIME CLOCK, DMA28
DS1643P-100 0 TIMER(S), REAL TIME CLOCK, DMA34
DS1643P-70 0 TIMER(S), REAL TIME CLOCK, DMA34
DS1643-70 0 TIMER(S), REAL TIME CLOCK, DMA28
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS1642-100+ 功能描述:實(shí)時(shí)時(shí)鐘 NV Timekeeping RAM 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
DS1642-12 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Real-Time Clock
DS1642-120 制造商:未知廠家 制造商全稱:未知廠家 功能描述:IC-16K CMOS NVRAM
DS1642-15 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Real-Time Clock
DS1642-70 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