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參數資料
| 型號： | DS14287 |
| 英文描述： | Real Time Clock with NV RAM Control |
| 中文描述： | 實時時鐘，帶有非易失RAM控制器 |
| 文件頁數： | 4/25頁 |
| 文件大小： | 303K |
| 代理商： | DS14287 |
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 V
CC
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 V
CC
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 V
CC
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PDF資料 |
PDF描述 |
|---|---|
| DS14285-DS14287 | Real Time Clock with NV RAM Control |
| DS14285 | Real Time Clock with NV RAM Control |
| DS14285N | Real Time Clock with NV RAM Control |
| DS14285Q | Real Time Clock with NV RAM Control |
| DS14285QN | Real Time Clock with NV RAM Control |
相關代理商/技術參數 |
參數描述 |
|---|---|
| DS14287+ | 功能描述:實時時鐘 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 時間格式:HH:MM:SS RTC 存儲容量: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: 安裝風格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube |
| DS1-48-0001 | 功能描述:固定電感器 DS Storage choke 3.15A RoHS:否 制造商:AVX 電感:10 uH 容差:20 % 最大直流電流:1 A 最大直流電阻:0.075 Ohms 工作溫度范圍:- 40 C to + 85 C 自諧振頻率:38 MHz Q 最小值:40 尺寸:4.45 mm W x 6.6 mm L x 2.92 mm H 屏蔽:Shielded 端接類型:SMD/SMT 封裝 / 箱體:6.6 mm x 4.45 mm |
| DS1-48-0002 | 功能描述:固定電感器 DS Storage choke 4A RoHS:否 制造商:AVX 電感:10 uH 容差:20 % 最大直流電流:1 A 最大直流電阻:0.075 Ohms 工作溫度范圍:- 40 C to + 85 C 自諧振頻率:38 MHz Q 最小值:40 尺寸:4.45 mm W x 6.6 mm L x 2.92 mm H 屏蔽:Shielded 端接類型:SMD/SMT 封裝 / 箱體:6.6 mm x 4.45 mm |
| DS1-48-0003 | 制造商:Schurter Electronic Components 功能描述: |
| DS1-48-0004 | 制造商:Schurter Electronic Components 功能描述: |
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