參數(shù)資料
型號(hào)： DS14287
廠商： DALLAS SEMICONDUCTOR
元件分類： XO, clock
英文描述： Real Time Clock with NV RAM Control(帶非易失性RAM控制的實(shí)時(shí)時(shí)鐘)
中文描述： 1 TIMER(S), REAL TIME CLOCK, PDIP24
封裝： MODULE, DIP-24
文件頁(yè)數(shù)： 11/23頁(yè)
文件大小： 170K
代理商： DS14287
DS14285/DS14287
022798 11/23
REGISTERS
The DS14285/DS14287 has four control registers
which are accessible at all times, even during the
update cycle.
REGISTER A
MSB
BIT 7
LSB
BIT 0
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
UIP
DV2
DV1
DV0
RS3
RS2
RS1
RS0
UIP
The Update In Progress (UIP) bit is a status flag that can
be monitored. When the UIP bit is a one, the update
transfer will soon occur. When UIP is a zero, the update
transfer will not occur for at least 244
μ
s. The time, cal-
endar, and alarm information in RAM is fully available
for access when the UIP bit is zero. The UIP bit is read
only and is not affected by RESET. Writing the SET bit in
Register B to a one inhibits any update transfer and
clears the UIP status bit.
DV0, DV1, DV2
These three bits are used to turn the oscillator on or off
and to reset the countdown chain. A pattern of 010 is the
only combination of bits that will turn the oscillator on
and allow the RTC to keep time. A pattern of 11X will
enable the oscillator but holds the countdown chain in
reset. The next update will occur at 500 ms after a pat-
tern of 010 is written to DV0, DV1, and DV2.
RS3, RS2, RS1, RS0
These four rate–selection bits select one of the 13 taps
on the 15–stage divider or disable the divider output.
The tap selected can be used to generate an output
square wave (SQW pin) and/or a periodic interrupt. The
user can do one of the following:
1. Enable the interrupt with the PIE bit;
2. Enable the SQW output pin with the SQWE bit;
3. Enable both at the same time and the same rate; or
4. Enable neither.
Table 1 lists the periodic interrupt rates and the square
wave frequencies that can be chosen with the RS bits.
These four read/write bits are not affected by RESET.
REGISTER B
MSB
BIT 7
LSB
BIT 0
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
SET
PIE
AIE
UIE
SQWE
DM
24/12
DSE
SET
When the SET bit is a zero, the update transfer functions
normally by advancing the counts once per second.
When the SET bit is written to a one, any update transfer
is inhibited and the program can initialize the time and
calendar bytes without an update occurring in the midst
of initializing. Read cycles can be executed in a similar
manner. SET is a read/write bit that is not modified by
RESET or internal functions of the DS14285/DS14287.
PIE
The periodic interrupt enable PIE bit is a read/write bit
which allows the Periodic Interrupt Flag (PF) bit in Reg-
ister C to drive the IRQ pin low. When the PIE bit is set to
one, periodic interrupts are generated by driving the
IRQ pin low at a rate specified by the RS3-RS0 bits of
Register A. A zero in the PIE bit blocks the IRQ output
from being driven by a periodic interrupt, but the Peri-
odic Flag (PF) bit is still set at the periodic rate. PIE is not
modified by any internal DS14285/DS14287 functions,
but is cleared to zero on RESET.
AIE
The Alarm Interrupt Enable (AIE) bit is a read/write bit
which, when set to a one, permits the Alarm Flag (AF) bit
in register C to assert IRQ. An alarm interrupt occurs for
each second that the three time bytes equal the three
alarm bytes including a “don’t care” alarm code of binary
11XXXXXX. When the AIE bit is set to zero, the AF bit
does not initiate the IRQ signal. The RESET pin clears
AIE to zero. The internal functions of the
DS14285/DS14287 do not affect the AIE bit.
UIE
The Update Ended Interrupt Enable (UIE) bit is a read/
write that enables the Update End Flag (UF) bit in Regis-
ter C to assert IRQ. The RESET pin going low or the
SET bit going high clears to UIE bit.
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS14287+ 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
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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