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參數(shù)資料
| 型號(hào)： | DS1642-100 |
| 英文描述： | Nonvolatile Timekeeping RAM |
| 中文描述： | 非易失性內(nèi)存時(shí)鐘 |
| 文件頁(yè)數(shù)： | 2/11頁(yè) |
| 文件大?。?/td> | 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 V
CC
supply is in
an out-of-tolerance condition. This feature prevents loss of data from unpredictable system operation
brought on by low V
CC
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
V
CC
CE
V
IH
V
IL
V
IL
V
IL
X
X
OE
X
X
V
IL
V
IH
X
X
WE
X
V
IL
V
IH
V
IH
X
X
MODE
DESELECT
WRITE
READ
READ
DESELECT
DESELECT
DQ
POWER
STANDBY
ACTIVE
ACTIVE
ACTIVE
CMOS STANDBY
DATA RETENTION
MODE
HIGH Z
DATA IN
DATA OUT
HIGH Z
HIGH Z
HIGH Z
5 VOLTS ± 10%
<4.5 VOLTS >V
BAT
<V
BAT
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| DS1642-70 | Nonvolatile Timekeeping RAM |
| DS1642 | Nonvolatile Timekeeping RAM |
| DS1644-120 | Nonvolatile Timekeeping RAM |
| DS1644L-120 | Nonvolatile Timekeeping RAM |
| DS1644L-150 | Nonvolatile Timekeeping RAM |
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(chēng):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(chēng):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(chēng):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 |
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