參數(shù)資料
型號(hào)： DS1994
英文描述： 4kb Plus Time Memory iButton
中文描述： 4K位、帶有時(shí)鐘的存儲(chǔ)器iButton®
文件頁(yè)數(shù)： 4/22頁(yè)
文件大小： 254K
代理商： DS1994
DS1994
Figure 3. 1-WIRE CRC CODE
4 of 22
X
0
X
1
X
2
X
3
X
4
X
5
X
6
X
7
X
8
Polynomial = X
8
+ X
5
+ X
4
+ 1
1
st
STAGE
2
nd
STAGE
3
rd
STAGE
4
th
STAGE
6
th
STAGE
5
th
STAGE
7
th
STAGE
8
th
STAGE
INPUT DATA
MEMORY
The memory map in Figure 4 shows a 32-Byte page called the scratchpad, and additional 32-Byte pages
called memory. The DS1994 contains 16 pages that make up the 4096-bit SRAM. The DS1994 also
contains page 16, which has only 30 Bytes containing the timekeeping registers.
The scratchpad is an additional page that acts as a buffer when writing to memory. Data is first written to
the scratchpad where it can be read back. After the data has been verified, a copy scratchpad command
transfers the data to memory. This process ensures data integrity when modifying the memory.
TIMEKEEPING
A 32.768kHz crystal oscillator is used as the time base for the timekeeping functions. The oscillator can
be turned on or off by an enable bit in the control register. The oscillator must be on for the real-time
clock, interval timer, and cycle counter to function.
The timekeeping functions are double buffered. This feature allows the master to read time or count
without the data changing while it is being read. To accomplish this, a snapshot of the counter data is
transferred to holding registers that the user accesses. This occurs after the 8th bit of the read memory
function command.
Real-Time Clock
The real-time clock is a 5-Byte binary counter. It is incremented 256 times per second. The least
significant Byte is a count of fractional seconds. The upper 4 Bytes are a count of seconds. The real-time
clock can accumulate 136 years of seconds before rolling over. Time/date is represented by the number of
seconds since a reference point, which is determined by the user. For example, 12:00 A.M., January 1,
1970 could be a reference point.
相關(guān)PDF資料
PDF描述
DS1995 16-kbit Memory iButton
DS1995L-F5 16-kbit Memory iButton
DS1996 64kbit Memory iButtonTM
DS1996L-F5 64kbit Memory iButtonTM
DS2004SF24 Rectifier Diode
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS1994-LF5 制造商: 功能描述: 制造商:undefined 功能描述:
DS1994L-F5 功能描述:iButton RoHS:否 存儲(chǔ)類(lèi)型:SRAM 存儲(chǔ)容量:512 B 組織: 工作電源電壓:3 V to 5.25 V 接口類(lèi)型:1-Wire 最大工作溫度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封裝 / 箱體:F5 MicroCan 制造商:Maxim Integrated
DS1994L-F5+ 功能描述:iButton RoHS:否 存儲(chǔ)類(lèi)型:SRAM 存儲(chǔ)容量:512 B 組織: 工作電源電壓:3 V to 5.25 V 接口類(lèi)型:1-Wire 最大工作溫度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封裝 / 箱體:F5 MicroCan 制造商:Maxim Integrated
DS1994L-F5-W 功能描述:iButton RoHS:否 存儲(chǔ)類(lèi)型:SRAM 存儲(chǔ)容量:512 B 組織: 工作電源電壓:3 V to 5.25 V 接口類(lèi)型:1-Wire 最大工作溫度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封裝 / 箱體:F5 MicroCan 制造商:Maxim Integrated
DS1994-LFS 制造商: 功能描述: 制造商:undefined 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*