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参数资料
| 型号： | DS1921G-F5# |
| 厂商： | Maxim Integrated |
| 文件页数： | 9/42页 |
| 文件大小： | 0K |
| 描述： | IBUTTON THERMOCHRON F5 |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| RoHS指令信息： | IButton RoHS Compliance Plan |
| 标准包装： | 8 |
| 系列： | iButton® |
| 存储容量： | 512B |
| 存储器类型： | NVSRAM（非易失 SRAM） |
| 产品目录页面： | 1431 (CN2011-ZH PDF) |
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DS1921G
Thermochron iButton Device
MSB
LSB
8-BIT
CRC CODE
48-BIT SERIAL NUMBER
8-BIT FAMILY CODE
(21h)
MSB
LSB MSB
LSB MSB
LSB
Figure 3. 64-Bit Lasered ROM
POLYNOMIAL = X 8 + X 5 + X 4 + 1
1ST
STAGE
2ND
STAGE
3RD
STAGE
4TH
STAGE
5TH
STAGE
6TH
STAGE
7TH
STAGE
8TH
STAGE
X 0
X 1
X 2
X 3
X 4
X 5
X 6
X 7
X 8
INPUT DATA
Figure 4. 1-Wire CRC Generator
64-Bit Lasered ROM
Each DS1921G contains a unique ROM code that is 64
bits long. The first 8 bits are a 1-Wire family code. The
next 48 bits are a unique serial number. The last 8 bits
are a cyclic redundancy check (CRC) of the first 56 bits
(see Figure 3 for details). The 1-Wire CRC is generated
using a polynomial generator consisting of a shift regis-
ter and XOR gates as shown in Figure 4. The polynomi-
al is X 8 + X 5 + X 4 + 1. Additional information about the
1-Wire CRC is available in Application Note 27:
Understanding and Using Cyclic Redundancy Checks
with Maxim iButton Products.
The Shift register bits are initialized to 0. Then, starting
with the least significant bit of the family code, one bit at
a time is shifted in. After the 8th bit of the family code
has been entered, the serial number is then entered.
After the 48th bit of the serial number has been entered,
the Shift register contains the CRC value. Shifting in the
8 bits of CRC returns the Shift register to all zeros.
Maxim Integrated
Memory
Figure 5 shows the DS1921G memory map. The 4096-bit
general-purpose SRAM makes up pages 0 to 15. The
timekeeping, control, and counter registers fill page 16,
called register page (see Figure 6). Pages 17, 18, and
19 are assigned to storing the alarm timestamps and
durations. The temperature histogram bins begin at page
64 and use up to four pages. The data-log memory cov-
ers pages 128 to 191. Memory pages 20 to 63, 68 to
127, and 192 to 255 are reserved for future extensions.
The scratchpad is an additional page that acts as a
buffer when writing to the SRAM or the register page.
The memory pages 17 and higher are read only for the
user. They are written to or erased solely under the
supervision of the on-chip control logic.
9
相关PDF资料 |
PDF描述 |
|---|---|
| DS1921H-F5# | IBUTTON THERMOCHRON F5 |
| DS1921K# | KIT IBUTTON THERMOCHRON |
| DS1922E-F5# | IBUTTON TEMP LOGGER 4KBit F5 |
| DS1922L-F5# | IBUTTON TEMP LOGGER |
| DS1923-F5# | IBUTTON TEMP/HUMIDITY LOGGER F5 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| DS1921G-F5# | 功能描述:iButton Thermochron iButton RoHS:否 存储类型:SRAM 存储容量:512 B 组织: 工作电源电压:3 V to 5.25 V 接口类型:1-Wire 最大工作温度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封装 / 箱体:F5 MicroCan 制造商:Maxim Integrated |
| DS1921G-F5#W | 功能描述:iButton RoHS:否 存储类型:SRAM 存储容量:512 B 组织: 工作电源电压:3 V to 5.25 V 接口类型:1-Wire 最大工作温度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封装 / 箱体:F5 MicroCan 制造商:Maxim Integrated |
| DS1921G-F5/A0C | 功能描述:iButton RoHS:否 存储类型:SRAM 存储容量:512 B 组织: 工作电源电压:3 V to 5.25 V 接口类型:1-Wire 最大工作温度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封装 / 箱体:F5 MicroCan 制造商:Maxim Integrated |
| DS1921G-F5/A12 | 功能描述:iButton RoHS:否 存储类型:SRAM 存储容量:512 B 组织: 工作电源电压:3 V to 5.25 V 接口类型:1-Wire 最大工作温度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封装 / 箱体:F5 MicroCan 制造商:Maxim Integrated |
| DS1921G-F5/A12-W | 功能描述:iButton RoHS:否 存储类型:SRAM 存储容量:512 B 组织: 工作电源电压:3 V to 5.25 V 接口类型:1-Wire 最大工作温度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封装 / 箱体:F5 MicroCan 制造商:Maxim Integrated |
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