参数资料
型号: DS1986-F3
厂商: MAXIM INTEGRATED PRODUCTS INC
元件分类: Programmable ROM
英文描述: 64K X 1 OTPROM, MEDB2
封装: MICROCAN-2
文件页数: 7/28页
文件大小: 680K
代理商: DS1986-F3
DS1986
15 of 28
1-WIRE BUS SYSTEM
The 1-Wire bus is a system that has a single bus master and one or more slaves. In all instances, the
DS1986 is a slave device. The bus master is typically a microcontroller. The discussion of this bus
system is broken down into three topics: hardware configuration, transaction sequence, and 1-Wire
signaling (signal type and timing). A 1-Wire protocol defines bus transactions in terms of the bus state
during specified time slots that are initiated on the falling edge of sync pulses from the bus master. For a
more detailed protocol description, refer to Chapter 4 of the Book of DS19xx iButton Standards.
Hardware Configuration
The 1-Wire bus has only a single line by definition; it is important that each device on the bus be able to
drive it at the appropriate time. To facilitate this, each device attached to the 1-Wire bus must have an
open drain connection or 3-state outputs. The DS1986 is an open drain part with an internal circuit
equivalent to that shown in Figure 6. The bus master can be the same equivalent circuit. If a bidirectional
pin is not available, separate output and input pins can be tied together.
The bus master requires a pull-up resistor at the master end of the bus, with the bus master circuit
equivalent to the one shown in Figures 7a and 7b. The value of the pull-up resistor should be
approximately 5k
Ω for short line lengths.
A multidrop bus consists of a 1-Wire bus with multiple slaves attached. At regular speed the 1-Wire bus
has a maximum data rate of 16.3kbps. The speed can be boosted to 142kbps by activating the Overdrive
mode. If the bus master is also required to perform programming of the EPROM portions of the DS1986,
a programming supply capable of delivering up to 10 milliamps at 12 volts for 480
μs is required. The
idle state for the 1-Wire bus is high. If, for any reason, a transaction needs to be suspended, the bus
MUST be left in the idle state if the transaction is to resume. If this does not occur and the bus is left low
for more than 16
μs (overdrive speed) or more than 120 μs (regular speed), one or more of the devices on
the bus may be reset.
Transaction Sequence
The sequence for accessing the DS1986 via the 1-Wire port is as follows:
Initialization
ROM Function Command
Memory Function Command
Read/Write Memory/Status
INITIALIZATION
All transactions on the 1-Wire bus begin with an initialization sequence. The initialization sequence
consists of a reset pulse transmitted by the bus master followed by a presence pulse(s) transmitted by the
slave(s).
The presence pulse lets the bus master know that the DS1986 is on the bus and is ready to operate. For
more details, see the “1-Wire Signaling” section.
相关PDF资料
PDF描述
DS1986-F5 64K X 1 OTPROM, MADB2
DS1991L-F5 SPECIALTY MEMORY CIRCUIT, MEDB2
DS1994L-F5 SPECIALTY MEMORY CIRCUIT, MRDB2
DS1993L-F5 SPECIALTY MEMORY CIRCUIT, MRDB2
DS1992L-F5 SPECIALTY MEMORY CIRCUIT, MRDB2
相关代理商/技术参数
参数描述
DS1986-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
DS1986-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
DS1986F5 制造商:未知厂家 制造商全称:未知厂家 功能描述:EPROM|256X32X8|BUTTON|METAL
DS1986-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
DS1986-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