參數(shù)資料
型號(hào): CD1865
廠商: Intel Corp.
英文描述: Intelligent Eight-Channel Communications Controller
中文描述: 智能八通道通信控制器
文件頁(yè)數(shù): 37/150頁(yè)
文件大?。?/td> 871K
代理商: CD1865
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)當(dāng)前第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)第123頁(yè)第124頁(yè)第125頁(yè)第126頁(yè)第127頁(yè)第128頁(yè)第129頁(yè)第130頁(yè)第131頁(yè)第132頁(yè)第133頁(yè)第134頁(yè)第135頁(yè)第136頁(yè)第137頁(yè)第138頁(yè)第139頁(yè)第140頁(yè)第141頁(yè)第142頁(yè)第143頁(yè)第144頁(yè)第145頁(yè)第146頁(yè)第147頁(yè)第148頁(yè)第149頁(yè)第150頁(yè)
Intelligent Eight-Channel Communications Controller
CD1865
Datasheet
37
This method is called
Software Polled
. Polling is often used in situations where the host
system is primarily dedicated to servicing the serial channels and has few other tasks to
perform. It is usually better when the host CPU has a long interrupt context switch time. In this
method, the host periodically checks the CD1865s to determine if any service requests are
pending. If they are, the host acknowledges them in software and proceeds with the service.
One of the advantages of the CD1865 is that it allows the use of any of the above techniques, or a
combination. Such a combination is referred to as
Mixed-mode operation
. In a typical mixed-
mode design, normal interrupts are used to signal to the host that service is required. After the host
enters its interrupt service routine, it services the CD1865 that generated the service request. Then
the host polls the CD1865s to determine if more channels require service. If the host finds a
channel requiring service, it handles it in the usual manner, and then proceeds to poll for more
service requests. This process continues until all CD1865s are handled. Because the host is not
exiting and re-entering its own interrupt context each time, much host CPU time is saved, resulting
in even faster overall performance.
The Advantage of a mixed-mode design is that the software has complete control of whether to be
fully interrupt driven or to poll in certain circumstances. A mixed-mode design is recommended to
tune a system for optimum performance.
A CD1865 evaluation board can be employed to analyze CD1865 performance and evaluate
different software implementations. Intel testing (in an AT-compatible
386 machine) found that a
mixed-mode system provided the highest overall throughput with minimum host CPU loading.
This is generally found to be the case with host processors that have relatively long interrupt
response times, such as the Intel
386.
5.5.1
Method 1a
Full Interrupt
Type A, Three-Level Interrupt
with Three-Level Acknowledge
This method is illustrated in
Figure 8
. It is best-suited for 680X0-family processors. The three
CD1865 service request lines are connected to the Interrupt Priority Encoder. When the host
performs an interrupt acknowledgment cycle, the CD1865 responds with its vector. The host uses
this vector to jump directly to the appropriate service routine. Other methods can also be used with
a 680X0-based system.
相關(guān)PDF資料
PDF描述
CD22100 CMOS 4 x 4 Crosspoint Switch with Control Memory High-Voltage Type (20V Rating)
CD22100E CMOS 4 x 4 Crosspoint Switch with Control Memory High-Voltage Type (20V Rating)
CD22100F CMOS 4 x 4 Crosspoint Switch with Control Memory High-Voltage Type (20V Rating)
CD22101 CMOS 4 x 4 x 2 Crosspoint Switch with Control Memory
CD22101E CMOS 4 x 4 x 2 Crosspoint Switch with Control Memory
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
CD1865N 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC
CD1865P 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC
CD1866N 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC
CD1866P 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC
CD1867N 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC