- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385273 > DS1986 (Maxim Integrated Products, Inc.) 64K bit Add-Only iButton(64K位只加按鈕) PDF資料下載
參數(shù)資料
| 型號： | DS1986 |
| 廠商： | Maxim Integrated Products, Inc. |
| 英文描述： | 64K bit Add-Only iButton(64K位只加按鈕) |
| 中文描述： | 64K位只添加iButton® |
| 文件頁數(shù)： | 18/24頁 |
| 文件大小： | 164K |
| 代理商： | DS1986 |
DS1986
052298 18/24
Overdrive Skip ROM [3CH]
On a single–drop bus this command can save time by
allowing the bus master to access the memory functions
without providing the 64–bit ROM code. Unlike the normal
Skip ROM command the Overdrive Skip ROM sets the
DS1986 in the Overdrive Mode (OD=1). All communica-
tion following this command has to occur at Overdrive
Speed until a reset pulse of minimum 480
μ
s duration
resets all devices on the bus to regular speed (OD=0).
When issued on a multidrop bus this command will set
all Overdrive–capable devices into Overdrive mode. To
subsequently address a specific Overdrive–capable
device, a reset pulse at Overdrive speed has to be
issued followed by a Match ROM or Search ROM com-
mand sequence. This will shorten the time for the
search process. If more than one slave supporting
Overdrive is present on the bus and the Overdrive Skip
ROM command is followed by a read command, data
collision will occur on the bus as multiple slaves transmit
simultaneously (open drain pull–downs will produce a
wire–AND result).
Overdrive Match ROM [69H]
The Overdrive Match ROM command, followed by a
64–bit ROM sequence transmitted at Overdrive Speed,
allows the bus master to address a specific DS1986 on
a multidrop bus and to simultaneously set it in Overdrive
Mode. Only the DS1986 that exactly matches the 64–bit
ROM sequence will respond to the subsequent memory
function command. Slaves already in Overdrive mode
from a previous Overdrive Skip or Match command will
remain in Overdrive mode. All other slaves that do not
match the 64–bit ROM sequence or do not support
Overdrive will return to or remain at regular speed and
wait for a reset pulse of minimum 480
μ
s duration. The
Overdrive Match ROM command can be used with a
single or multiple devices on the bus.
1–Wire Signalling
The DS1986 requires strict protocols to insure data
integrity. The protocol consists of five types of signaling
on one line: Reset Sequence with Reset Pulse and
Presence Pulse, Write 0, Write 1, Read Data and Pro-
gram Pulse. All these signals except presence pulse are
initiated by the bus master. The DS1986 can communi-
cate at two different speeds, regular speed and Over-
drive Speed. If not explicitly set into the Overdrive Mode,
the DS1986 will communicate at regular speed. While in
Overdrive Mode the fast timing applies to all commu-
nication–related wave forms.
The initialization sequence required to begin any com-
munication with the DS1986 is shown in Figure 9. A
Reset Pulse followed by a Presence Pulse indicates the
DS1986 is ready to accept a ROM command. The bus
master transmits (TX) a reset pulse (t
RSTL
, minimum
480
μ
s at regular speed, 48
μ
s at Overdrive Speed). The
bus master then releases the line and goes into receive
mode (RX). The 1–Wire bus is pulled to a high state via
the pull–up resistor. After detecting the rising edge on
the data pin, the DS1986 waits (t
PDH
, 15–60
μ
s at regu-
lar speed, 2–6
μ
s at overdrive speed) and then transmits
the presence pulse (t
PDL
, 60–240
μ
s at regular speed,
8–24
μ
s at Overdrive Speed).
A Reset Pulse of 480
μ
s or longer will exit the Overdrive
Mode returning the device to regular speed. If the DS1986
is in Overdrive Mode and the Reset Pulse is no longer
than 80
μ
s the device will remain in Overdrive Mode.
Read/Write Time Slots
The definitions of write and read time slots are illustrated
in Figure 10. All time slots are initiated by the master
driving the data line low. The falling edge of the data line
synchronizes the DS1986 to the master by triggering a
delay circuit in the DS1986. During write time slots, the
delay circuit determines when the DS1986 will sample
the data line. For a read data time slot, if a “0” is to be
transmitted, the delay circuit determines how long the
DS1986 will hold the data line low overriding the 1 gen-
erated by the master. If the data bit is a “1”, the iButton
will leave the read data time slot unchanged.
PROGRAM PULSE
To copy data from the 8–bit scratchpad to the EPROM
Data or Status Memory, a program pulse of 12 volts is
applied to the data line after the bus master has con-
firmed that the CRC for the current byte is correct. Dur-
ing programming, the bus master controls the transition
from a state where the data line is idling high via the
pull–up resistor to a state where the data line is actively
driven to a programming voltage of 12 volts providing a
minimum of 10 mA of current to the DS1986. This pro-
gramming voltage (Figure 11) should be applied for 480
μ
s, after which the bus master returns the data line to an
idle high state controlled by the pull–up resistor. Note
that due to the high voltage programming requirements
for any 1–Wire EPROM device, it is not possible to mul-
ti–drop non–EPROM based 1–Wire devices with the
DS1986 during programming. An internal diode within
the non–EPROM based 1–Wire devices will attempt to
clamp the data line at approximately 8 volts and could
potentially damage these devices.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| DS2045W | 3.3V Single-Piece 1Mb Nonvolatile SRAM |
| DS2045W-100 | 3.3V Single-Piece 1Mb Nonvolatile SRAM |
| DS2151Q | T1 Single-Chip Transceiver(T1單片收發(fā)器) |
| DS2154 | Enhanced E1 Single Chip Transceiver(改進型E1單片收發(fā)器) |
| DS2164Q | G.726 ADPCM Processor(G.726自適應(yīng)音頻脈沖編碼處理器) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS1986+F3 | 制造商:Maxim Integrated Products 功能描述:ADD-O IBTN 64KB, F3 (GENERIC) LFREE - Rail/Tube |
| DS19860-F3-W | 功能描述:iButton RoHS:否 存儲類型:SRAM 存儲容量:512 B 組織: 工作電源電壓:3 V to 5.25 V 接口類型: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 |
| DS1986-F3 | 功能描述:iButton RoHS:否 存儲類型:SRAM 存儲容量:512 B 組織: 工作電源電壓:3 V to 5.25 V 接口類型: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 |
| DS1986-F3# | 功能描述:iButton RoHS:否 存儲類型:SRAM 存儲容量:512 B 組織: 工作電源電壓:3 V to 5.25 V 接口類型: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 |
| DS1986-F3+ | 功能描述:iButton RoHS:否 存儲類型:SRAM 存儲容量:512 B 組織: 工作電源電壓:3 V to 5.25 V 接口類型: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 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。