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參數(shù)資料
| 型號(hào)： | DS1742W-150 |
| 英文描述： | Y2KC Nonvolatile Timekeeping RAM |
| 中文描述： | Y2KC非易失內(nèi)存時(shí)鐘 |
| 文件頁(yè)數(shù)： | 3/12頁(yè) |
| 文件大?。?/td> | 163K |
| 代理商： | DS1742W-150 |
DS1742
3 of 12
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 (bit 7) of the seconds registers,
see Table 2. Setting it to a 1 stops the oscillator.
FREQUENCY TEST BIT
As shown in Table 2, 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,
OE
low,
WE
high, and address for seconds register remain valid and
stable).
CLOCK ACCURACY
The DS1742 is guaranteed to keep time accuracy to within
±
1 minute per month at 25
°
C. The RTC is
calibrated at the factory by Dallas Semiconductor using nonvolatile tuning elements. The DS1742 does
not require additional calibration. For this reason, methods of field clock calibration are not available and
not necessary. Clock accuracy is also effected by the electrical environment and caution should be taken
to place the RTC in the lowest level EMI section of the PCB layout. For additional information please
see application note 58.
DS1742 REGISTER MAP
Table 2
DATA
B
4
ADDRESS
B
7
B
6
B
5
B
3
B
2
YEAR
MONTH
DATE
B
1
B
0
FUNCTION/RANGE
7FF
7FE
7FD
7FC
7FB
7FA
7F9
7F8
10 Year
YEAR
MONTH
DATE
DAY
HOUR
MINUTES
SECONDS
CONTROL
00-99
01-12
01-31
01-07
00-23
00-59
00-59
00-39
X
X
BF
X
X
X
X
FT
X
X
10 Mo
10 Date
X
X
X
DAY
10 HOUR
HOUR
MINUTES
SECONDS
CENTURY
10 MINUTES
10 SECONDS
10 CENTURY
OSC
W
R
OSC
= STOP BIT
W = WRITE BIT
R = READ BIT
X = SEE NOTE BELOW
FT = FREQUENCY TEST
BF = BATTERY FLAG
NOTE:
All indicated “X” bits are not dedicated to any particular function and can be used as normal RAM bits.
RETRIEVING DATA FROM RAM OR CLOCK
The DS1742 is in the read mode whenever
OE
(output enable) is low,
WE
(write enable) is high, and
CE
(chip enable) is low. The device architecture allows ripplethrough access to any of the address locations
in the NV SRAM. Valid data will be available at the DQ pins within t
AA
after the last address input is
stable, providing that the
CE
, and
OE
access times and states are satisfied. If
CE
, or
OE
access times
and states are not met, valid data will be available at the latter of chip enable access (t
CEA
) or at output
enable access time (t
OEA
). The state of the data input/output pins (DQ) is controlled by
CE
, and
OE
. If
the outputs are activated before t
AA
, the data lines are driven to an intermediate state until t
AA
. If the
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS1742W-150+ | 功能描述:實(shí)時(shí)時(shí)鐘 Timekeeping NV 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 |
| DS1743 | 制造商:MAXIM 制造商全稱(chēng):Maxim Integrated Products 功能描述:Y2K-Compliant, Nonvolatile Timekeeping |
| DS1743-100 | 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 |
| DS1743-100 IND | 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 |
| DS1743-100+ | 功能描述:實(shí)時(shí)時(shí)鐘 Timekeeping NV 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 |
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