參數(shù)資料
型號(hào)： DS14285QN
廠商： DALLAS SEMICONDUCTOR
元件分類： Timer or RTC
英文描述： 1 TIMER(S), REAL TIME CLOCK, PQCC28
封裝： PLASTIC, LCC-28
文件頁(yè)數(shù)： 20/25頁(yè)
文件大?。?/td> 303K
代理商： DS14285QN
DS14285/DS14287
4 of 25
R/ W (Read/Write Input) - The R/ W pin also has two modes of operation. When the MOT pin is
connected to VCC for Motorola timing, R/ W is at a level which indicates whether the current cycle is a
read or write. A read cycle is indicated with a high level on R/ W while DS is high. A write cycle is
indicated when R/ W is low during DS.
When the MOT pin is connected to GND for Intel timing, the R/ W signal is an active low signal called
WR
. In this mode the R/ W pin has the same meaning as the Write Enable signal ( WE ) on generic
RAMs.
CS
(Chip Select Input) - The Chip Select signal must be asserted low for a bus cycle in the
DS14285/DS14287 to be accessed. CS must be kept in the active state during DS for Motorola timing
and during RD and WR for Intel timing. Bus cycles which take place without asserting CS will latch
addresses but no access will occur. When VCC is below 4.25 volts, the DS14285/DS14287 internally
inhibits access cycles by internally disabling the CS input. This action protects both the real time clock
data and RAM data during power outages.
IRQ
(Interrupt Request Output) - The IRQ pin is an active low output of the DS14285/DS14287 that
can be used as an interrupt input to a processor. The IRQ output remains low as long as the status bit
causing the interrupt is present and the corresponding interrupt-enable bit is set. To clear the IRQ pin the
processor program normally reads the C register. The RESET pin also clears pending interrupts.
When no interrupt conditions are present, the IRQ level is in the high impedance state. Multiple
interrupting devices can be connected to an IRQ bus. The IRQ bus is an open drain output and requires an
external pull-up resistor.
RESET
(Reset Input) - The RESET pin has no effect on the clock, calendar, or RAM. On power-up the
RESET
pin can be held low for a time in order to allow the power supply to stabilize. The amount of time
that RESET is held low is dependent on the application. However, if RESET is used on power-up, the
time RESET is low should exceed 200 ms to make sure that the internal timer that controls the
DS14285/DS14287 on power-up has timed out. When RESET is low and VCC is above 4.25 volts, the
following occurs:
A. Periodic Interrupt Enable (PEI) bit is cleared to 0.
B. Alarm Interrupt Enable (AIE) bit is cleared to 0.
C. Update Ended Interrupt Flag (UF) bit is cleared to 0.
D. Interrupt Request Status Flag (IRQF) bit is cleared to 0.
E. Periodic Interrupt Flag (PF) bit is cleared to 0.
F. The device is not accessible until RESET is returned high.
G. Alarm Interrupt Flag (AF) bit is cleared to 0.
H. IRQ pin is in the high impedance state.
I.
Square Wave Output Enable ( SQWE ) bit is cleared to 0.
J. Update Ended Interrupt Enable (UIE) is cleared to 0.
K. CEO is driven high.
相關(guān)PDF資料
PDF描述
DS14285S 1 TIMER(S), REAL TIME CLOCK, PDSO24
DS14285N 1 TIMER(S), REAL TIME CLOCK, PDIP24
DS14285SN 1 TIMER(S), REAL TIME CLOCK, PDSO24
DS14285Q 1 TIMER(S), REAL TIME CLOCK, PQCC28
DS14285 1 TIMER(S), REAL TIME CLOCK, PDIP24
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS14285QN+ 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
DS14285S 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
DS14285S/T&R 制造商:Maxim Integrated Products 功能描述:IC RTC W/NV RAM CNTRL 24-SOIC
DS14285S/T&R 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
DS14285S/TR 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Real-Time Clock with NV RAM
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