参数资料
型号: DS1553WP-150
厂商: MAXIM INTEGRATED PRODUCTS INC
元件分类: Timer or RTC
英文描述: 0 TIMER(S), REAL TIME CLOCK, DMA34
封装: POWERCAP MODULE-34
文件页数: 23/25页
文件大小: 546K
代理商: DS1553WP-150
DS1553 64kB, Nonvolatile, Year-2000-Compliant Timekeeping RAM
7 of 23
READING THE CLOCK
When reading the RTC data, it is recommended to halt updates to the external set of double-buffered RTC
registers. This puts the external registers into a static state, allowing data to be read without register
values changing during the read process. Normal updates to the internal registers continue while in this
state. External updates are halted when a 1 is written into the read bit, B6 of the Control register (1FF8h).
As long as a 1 remains in the Control register read bit, updating is halted. After a halt is issued, the
registers reflect the RTC count (day, date, and time) that was current at the moment the halt command
was issued. Normal updates to the external set of registers resume within 1 second after the read bit is set
to 0 for a minimum of 500
ms. The read bit must be 0 for a minimum of 500ms to ensure the external
registers are updated.
SETTING THE CLOCK
The 8th bit, B7 of the Control register, is the write bit. Setting the write bit to 1, like the read bit, halts
updates to the DS1553 (1FF8h–1FFFh) registers. After setting the write bit to 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 0
then transfers the values written to the internal RTC registers and allows normal operation to resume.
CLOCK ACCURACY (DIP MODULE)
The DS1553 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. The electrical environment also affects clock accuracy and caution should be taken to place the
RTC in the lowest level EMI section of the PC board layout. For additional information, refer to
Application Note 58: Crystal Considerations with Dallas Real-Time Clocks, available on our website at
CLOCK ACCURACY (PowerCap MODULE)
The DS1553 and DS9034PCX are each individually tested for accuracy. Once mounted together, the
module typically keeps time accuracy to within
±1.53 minutes per month (35ppm) at +25°C. The
electrical environment affects clock accuracy and caution should be taken to place the RTC in the lowest
level EMI section of the PC board layout. For additional information, refer to Application Note 58:
Crystal
Considerations
with
Dallas
Real-Time
Clocks,
available
on
our
website
at
FREQUENCY TEST MODE
The DS1553 frequency test mode uses the open-drain IRQ /FT output. With the oscillator running, the
IRQ
/FT output toggles at 512Hz when the FT bit is 1, the Alarm Flag Enable bit (AE) is 0, and the
Watchdog Steering bit (WDS) is 1 or the Watchdog register is reset (Register 1FF7h = 00h). The IRQ /FT
output and the frequency test mode can be used as a measure of the actual frequency of the 32.768kHz
RTC oscillator. The IRQ /FT pin is an open-drain output that requires a pullup resistor for proper
operation. The FT bit is cleared to 0 on power-up.
相关PDF资料
PDF描述
DS1553WP-120 0 TIMER(S), REAL TIME CLOCK, DMA34
DS1553-100 0 TIMER(S), REAL TIME CLOCK, DMA28
DS1553W-120 0 TIMER(S), REAL TIME CLOCK, DMA28
DS1553P-100 0 TIMER(S), REAL TIME CLOCK, DMA34
DS1554-70 0 TIMER(S), REAL TIME CLOCK, PDMA32
相关代理商/技术参数
参数描述
DS1553WP-150+ 功能描述:实时时钟 64kB NV RAM Timekeeper RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube
DS1554 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:256K NV Y2KC Timekeeping RAM
DS1554-100 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:256K NV Y2KC Timekeeping RAM
DS1554-70 功能描述:实时时钟 RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube
DS1554-70+ 功能描述:实时时钟 256kB NV RAM Timekeeper RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube