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參數(shù)資料
| 型號(hào)： | DS1642-70 |
| 英文描述： | Nonvolatile Timekeeping RAM |
| 中文描述： | 非易失性?xún)?nèi)存時(shí)鐘 |
| 文件頁(yè)數(shù)： | 3/11頁(yè) |
| 文件大小： | 138K |
| 代理商： | DS1642-70 |
DS1642
3 of 11
SETTING THE CLOCK
The 8th bit of the control register is the write bit. Setting the write bit to a 1, like the read bit, halts
updates to the DS1642 registers. The user can then load them with the correct day, date and time data in
24-hour BCD format. Resetting the write bit to a 0 then transfers those values to the actual clock counters
and allows normal operation to resume.
STOPPING AND STARTING THE CLOCK OSCILLATOR
The clock oscillator may be stopped at any time. To increase the shelf life, the oscillator can be turned off
to minimize current drain from the battery. The
OSC
bit is the MSB for the seconds registers. Setting it to
a 1 stops the oscillator.
FREQUENCY TEST BIT
Bit 6 of the day byte is the frequency test bit. When the frequency test bit is set to logic 1 and the
oscillator is running, the LSB of the seconds register will toggle at 512 Hz. When the seconds register is
being read, the DQ0 line will toggle at the 512 Hz frequency as long as conditions for access remain valid
(i.e.,
CE
low, and
OE
low) and address for seconds register remain valid and stable.
CLOCK ACCURACY
The DS1642 is guaranteed to keep time accuracy to within
±
1 minute per month at 25
°
C. The clock is
calibrated at the factory by Dallas Semiconductor using special calibration nonvolatile tuning elements.
The DS1642 does not require additional calibration and temperature deviations will have a negligible
effect in most applications. For this reason, methods of field clock calibration are not available and not
necessary.
DS1642 REGISTER MAP – BANK1
Table 2
DATA
B4
-
-
-
X
-
-
-
X
ADDRESS
B7
-
X
X
X
X
X
B6
-
X
X
FT
X
-
-
R
B5
-
X
-
X
-
-
-
X
B3
-
-
-
X
-
-
-
X
B2
-
-
-
-
-
-
-
X
B1
-
-
-
-
-
-
-
X
B0
-
-
-
-
-
-
-
X
FUNCTION
7FF
7FE
7FD
7FC
7FB
7FA
7F9
7F8
YEAR
MONTH
DATE
DAY
HOUR
MINUTES
SECONDS
CONTROL
00-99
01-12
01-31
00-23
00-59
00-59
00-59
A
OSC
W
OSC
= STOP BIT
W = WRITE BIT
R = READ BIT
X = UNUSED
FT = FREQUENCY TEST
NOTE:
All indicated “X” bits are not dedicated to any particular function and can be used as normal RAM bits.
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 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(xiàn)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 |
| DS1642-85 | 制造商:Maxim Integrated Products 功能描述:REAL TIME CLOCK PARALLEL 2KBYTE 24PIN EDIP - Bulk |
| DS1642-85+ | 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(xiàn)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 |
| DS-1642ZJ | 制造商:Hikvision USA 功能描述:6" Outdoor Speed Dome Bracket, White, Ceiling Mount Bracket |
| DS1643 | 制造商:MAXIM 制造商全稱(chēng):Maxim Integrated Products 功能描述:Nonvolatile Timekeeping RAMs |
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