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參數(shù)資料
| 型號(hào)： | DS1556 |
| 廠商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分類： | Timer or RTC |
| 英文描述： | REAL TIME CLOCK, DMA32 |
| 封裝： | PLASTIC, MODULE, DIP-32 |
| 文件頁數(shù)： | 18/20頁 |
| 文件大小： | 282K |
| 代理商： | DS1556 |
DS1556
7 of 20
SETTING THE CLOCK
The MSB bit, B7, of the Control Register is the write bit. Setting the write bit to a 1, like the read bit,
halts updates to the DS1556 (1FFF8h-1FFFFh) registers. After setting the write bit to a 1, RTC Registers
can be loaded with the desired RTC count (day, date, and time) in 24-hour BCD format. Setting the write
bit to a 0 then transfers the values written to the internal RTC Registers and allows normal operation to
resume.
CLOCK ACCURACY (DIP MODULE)
The DS1556 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, and 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.
CLOCK ACCURACY (POWERCAP MODULE)
The DS1556 and DS9034PCX are each individually tested for accuracy. Once mounted together, the
module will typically keep time accuracy to within
±1.53 minutes per month (35 ppm) at 25°C. 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.
FREQUENCY TEST MODE
The DS1556 frequency test mode uses the open drain IRQ /FT output. With the oscillator running, the
IRQ
/FT output will toggle at 512 Hz when the FT bit is a 1, the Alarm Flag Enable bit (AE) is a 0, and
the Watchdog Steering bit (WDS) is a 1 or the Watchdog Register is reset (Register 1FFF7h = 00h). The
IRQ
/FT output and the frequency test mode can be used as a measure of the actual frequency of the
32.768 kHz RTC oscillator. The IRQ /FT pin is an open drain output which requires a pull-up resistor for
proper operation. The FT bit is cleared to a 0 on power-up.
USING THE CLOCK ALARM
The alarm settings and control for the DS1556 reside within Registers 1FFF2h-1FFF5h. Register 1FFF6h
contains two alarm enable bits: Alarm Enable (AE) and Alarm in Backup Enable (ABE). The AE and
ABE bits must be set as described below for the IRQ /FT output to be activated for a matched alarm
condition.
The alarm can be programmed to activate on a specific day of the month or repeat every day, hour,
minute, or second. It can also be programmed to go off while the DS1556 is in the battery-backed state of
operation to serve as a system wake-up. Alarm mask bits AM1-AM4 control the alarm mode. Table 3
shows the possible settings. Configurations not listed in the table default to the once per second mode to
notify the user of an incorrect alarm setting.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| DS1556P | REAL TIME CLOCK, DMA34 |
| DS1557WP-120 | 0 TIMER(S), REAL TIME CLOCK, DMA34 |
| DS1557P-70 | 0 TIMER(S), REAL TIME CLOCK, DMA34 |
| DS1620R | DIGITAL TEMP SENSOR-SERIAL, 9BIT(s), RECTANGULAR, SURFACE MOUNT |
| DS1620 | DIGITAL TEMP SENSOR-SERIAL, 9BIT(s), 0.50Cel, RECTANGULAR, SURFACE MOUNT |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS1556_10 | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:1M, Nonvolatile, Y2K-Compliant Timekeeping RAM |
| DS1556-70 | 功能描述:實(shí)時(shí)時(shí)鐘 1M NV RAM Timekeeper 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 |
| DS1556-70+ | 功能描述:實(shí)時(shí)時(shí)鐘 1M NV RAM Timekeeper 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 |
| DS1556-70IND | 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 |
| DS1556-70IND+ | 功能描述:實(shí)時(shí)時(shí)鐘 1M NV RAM Timekeeper 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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