1024-Bit EEPROM iButton
POLYNOMIAL = X 16 + X 15 + X 2 + 1
X 0
1ST
STAGE
X 1
2ND
STAGE
X 2
3RD
STAGE
X 3
4TH
STAGE
X 4
5TH
STAGE
X 5
6TH
STAGE
X 6
7TH
STAGE
X 7
8TH
STAGE
9TH
STAGE
10TH
STAGE
11TH
STAGE
12TH
STAGE
13TH
STAGE
14TH
STAGE
15TH
STAGE
16TH
STAGE
X 8
X 9
X 10
X 11
X 12
X 13
X 14
X 15
X 16
CRC OUTPUT
INPUT DATA
Figure 13. CRC-16 Hardware Description and Polynomial
by the bus master. The DS1972 transmits this CRC only
if E[2:0] = 111b.
With the Read Scratchpad command, the CRC is gen-
erated by first clearing the CRC generator and then
shifting in the command code, the target addresses
TA1 and TA2, the E/S byte, and the scratchpad data as
they were sent by the DS1972. The DS1972 transmits
this CRC only if the reading continues through the end
of the scratchpad. For more information on generating
CRC values, refer to Application Note 27.
Command-Specific 1-Wire Communication Protocol—Legend
SYMBOL
RST
PD
Select
WS
RS
CPS
RM
TA
TA-E/S
<8 –T[2:0] bytes>
<Data to EOM>
CRC-16
FF Loop
AA Loop
Programming
DESCRIPTION
1-Wire reset pulse generated by master.
1-Wire presence pulse generated by slave.
Command and data to satisfy the ROM function protocol.
Command “Write Scratchpad.”
Command “Read Scratchpad.”
Command “Copy Scratchpad.”
Command “Read Memory.”
Target address TA1, TA2.
Target address TA1, TA2 with E/S byte.
Transfer of as many bytes as needed to reach the end of the scratchpad for a given target address.
Transfer of as many data bytes as are needed to reach the end of the memory.
Transfer of an inverted CRC-16.
Indefinite loop where the master reads FF bytes.
Indefinite loop where the master reads AA bytes.
Data transfer to EEPROM; no activity on the 1-Wire bus permitted during this time.
20
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相关代理商/技术参数
DS1972-F5 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:1024-Bit EEPROM iButton
DS1972-F5# 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
DS1972-F5+ 功能描述:iButton 1024-Bit EEPROM 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
DS1973 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:4-kbit EEPROM iButton
DS1973+F3 制造商:Maxim Integrated Products 功能描述:EEPROM SERL-1WIRE 4KBIT 16PAGES X 256 3.3V/5V F3 CA - Rail/Tube
DS1973+F5 制造商:Maxim Integrated Products 功能描述:IC MEMORY I BUTTON 1973
DS1973-F3 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
DS1973-F3# 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