- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄97863 > DS1742W-150 (DALLAS SEMICONDUCTOR) 0 TIMER(S), REAL TIME CLOCK, DMA24 PDF資料下載
參數(shù)資料
| 型號： | DS1742W-150 |
| 廠商： | DALLAS SEMICONDUCTOR |
| 元件分類： | Timer or RTC |
| 英文描述： | 0 TIMER(S), REAL TIME CLOCK, DMA24 |
| 封裝： | DIP-24 |
| 文件頁數(shù)： | 5/12頁 |
| 文件大?。?/td> | 162K |
| 代理商： | DS1742W-150 |
DS1742
2 of 12
The RTC clock registers are double-buffered to avoid access of incorrect data that can occur during clock
update cycles.
The double buffered system also prevents time loss as the timekeeping countdown
continues unabated by access to time register data.
The DS1742 also contains its own power-fail
circuitry, which deselects the device when the VCC supply is in an out of tolerance condition. This feature
prevents loss of data from unpredictable system operation brought on by low VCC as errant access and
update cycles are avoided.
CLOCK OPERATIONS-READING THE CLOCK
While the double-buffered register structure reduces the chance of reading incorrect data, internal updates
to the DS1742 clock registers should be halted before clock data is read to prevent reading of data in
transition. However, halting the internal clock register updating process does not affect clock accuracy.
Updating is halted when a 1 is written into the read bit, bit 6 of the century register, see Table 2. As long
as a 1 remains in that position, updating is halted. After a halt is issued, the registers reflect the count,
that is day, date, and time that was current at the moment the halt command was issued. However, the
internal clock registers of the double-buffered system continue to update so that the clock accuracy is not
affected by the access of data. All of the DS1742 registers are updated simultaneously after the internal
clock register updating process has been re-enabled. Updating is within a second after the read bit is
written to 0. The READ bit must be a zero for a minimum of 500
s to ensure the external registers will
be updated.
DS1742 BLOCK DIAGRAM Figure 1
DS1742 TRUTH TABLE Table 1
VCC
CE
OE
WE
MODE
DQ
POWER
VIH
X
DESELECT
HIGH-Z
STANDBY
VIL
XVIL
WRITE
DATA IN
ACTIVE
VIL
VIH
READ
DATA OUT
ACTIVE
VCC>VPF
VIL
VIH
READ
HIGH-Z
ACTIVE
VSO<VCC<VPF
X
DESELECT
HIGH-Z
CMOS STANDBY
VCC<VSO<VPF
X
DESELECT
HIGH-Z
DATA RETENTION MODE
SETTING THE CLOCK
As shown in Table 2, bit 7 of the century register is the write bit. Setting the write bit to a 1, like the read
bit, halts updates to the DS1742 registers. The user can then load them with the correct day, date and
time data in 24-hour BCD format. Resetting the write bit to a 0 then transfers those values to the actual
clock counters and allows normal operation to resume.
相關PDF資料 |
PDF描述 |
|---|---|
| DS1743P-70 | 0 TIMER(S), REAL TIME CLOCK, DMA34 |
| DS1743-70 | 0 TIMER(S), REAL TIME CLOCK, DMA28 |
| DS1743W-120 | 0 TIMER(S), REAL TIME CLOCK, DMA28 |
| DS9034PCX | 0 TIMER(S), REAL TIME CLOCK, DMA34 |
| DS1743-100 | 0 TIMER(S), REAL TIME CLOCK, DMA28 |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| DS1742W-150+ | 功能描述:實時時鐘 Timekeeping NV RAM 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 |
| DS1743 | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:Y2K-Compliant, Nonvolatile Timekeeping |
| DS1743-100 | 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 |
| DS1743-100 IND | 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 |
| DS1743-100+ | 功能描述:實時時鐘 Timekeeping NV RAM 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 |
發(fā)布緊急采購，3分鐘左右您將得到回復。