- 您現在的位置：買賣IC網 > PDF目錄379181 > DS1923 Hygrochron Temperature/Humidity Logger iButton with 8kB Data Log Memory PDF資料下載
參數資料
| 型號： | DS1923 |
| 英文描述： | Hygrochron Temperature/Humidity Logger iButton with 8kB Data Log Memory |
| 文件頁數： | 37/52頁 |
| 文件大?。?/td> | 495K |
| 代理商： | DS1923 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁當前第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁
DS1923: Hygrochron Temperature/Humidity Logger iButton with 8kB Data Log Memory
devices exist with both states of the bit. By choosing which state to write, the bus master branches in the romcode
tree. After one complete pass, the bus master knows the registration number of a single device. Additional passes
identify the registration numbers of the remaining devices. Refer to App Note 187:
1-Wire Search Algorithm
for a
detailed discussion, including an example.
Conditional Search [ECh]
The Conditional Search ROM command operates similarly to the Search ROM command except that only those
devices, which fulfill certain conditions, participate in the search. This function provides an efficient means for the
bus master to identify devices on a multidrop system that have to signal an important event. After each pass of the
conditional search that successfully determined the 64-bit ROM code for a specific device on the multidrop bus,
that particular device can be individually accessed as if a Match ROM had been issued, since all other devices
have dropped out of the search process and will be waiting for a reset pulse.
The DS1923 responds to the conditional search if one of the five alarm flags of the Alarm Status Register (address
0214h) reads 1. The humidity and temperature alarm only occurs if enabled (see
Temperature Sensor Alarm
and
Humidity Alarm
). The BOR alarm is always enabled. The first alarm that occurs makes the device respond to the
Conditional Search command.
Skip ROM [CCh]
This command can save time in a single-drop bus system by allowing the bus master to access the memory
functions without providing the 64-bit ROM code. If more than one slave is present on the bus and, for example, a
Read command is issued following the Skip ROM command, data collision occurs on the bus as multiple slaves
transmit simultaneously (open-drain pulldowns produce a wired-AND result).
Resume Command [A5h]
The DS1923 needs to be accessed several times before a mission starts. In a multidrop environment this means
that the 64-bit ROM code after a Match ROM command has to be repeated for every access. To maximize the data
throughput in a multidrop environment, the Resume function was implemented. This function checks the status of
the RC bit and, if it is set, directly transfers control to the Memory/Control functions, similar to a Skip ROM
command. The only way to set the RC bit is through successfully executing the Match ROM, Search ROM or
Overdrive Match ROM command. Once the RC bit is set, the device can repeatedly be accessed through the
Resume Command function. Accessing another device on the bus will clear the RC bit, preventing two or more
devices from simultaneously responding to the Resume Command function.
Overdrive Skip ROM [3Ch]
On a single-drop bus this command can save time by allowing the bus master to access the memory/control func-
tions without providing the 64-bit ROM code. Unlike the normal Skip ROM command, the Overdrive Skip ROM sets
the DS1923 in the Overdrive mode (OD = 1). All communication following this command has to occur at Overdrive
speed until a reset pulse of minimum 690μs duration resets all devices on the bus to standard speed (OD = 0).
When issued on a multidrop bus this command will set all Overdrive-supporting devices into Overdrive mode. To
subsequently address a specific Overdrive-supporting device, a reset pulse at Overdrive speed has to be issued
followed by a Match ROM or Search ROM command sequence. This speeds up 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 occurs on the bus as multiple slaves transmit simultaneously (open-drain
pulldowns will produce a wired-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 DS1923 on a multidrop bus and to simultaneously set it in Overdrive mode.
Only the DS1923 that exactly matches the 64-bit ROM sequence will respond to the subsequent memory/control
function command. Slaves already in Overdrive mode from a previous Overdrive Skip or successful Overdrive
Match command remains in Overdrive mode. All overdrive-capable slaves return to standard speed at the next
Reset Pulse of minimum 690μs duration. The Overdrive Match ROM command can be used with a single or
multiple devices on the bus.
37 of 52
相關PDF資料 |
PDF描述 |
|---|---|
| DS1923-F5 | Hygrochron Temperature/Humidity Logger iButton with 8kB Data Log Memory |
| DS1990 | Serial Number iButton |
| DS1990A | Serial Number iButton |
| DS1990A-F5 | Serial Number iButton |
| DS1994L-F5 | 4kb Plus Time Memory iButton |
相關代理商/技術參數 |
參數描述 |
|---|---|
| DS1923_1 | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Hygrochron Temperature/Humidity Logger iButton with 8kB Data Log Memory |
| DS1923_11 | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:Hygrochron Temperature/Humidity Logger |
| DS1923-F5 | 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 |
| DS1923-F5# | 功能描述:iButton Hygrochron Temp/Hum Logger w/8KB DataLog 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 |
| DS1923-F5#W | 功能描述:iButton Hygrochron Temp/Hum Logger w/8KB DataLog 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。