【单选题】
89S51的内部程序存储器与数据存储器容量各为多少？___
A. 64KB、128B
B. 4KB、64KB
C. 4KB、128B
D. 8KB、256B
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相关试题
【单选题】
89S51比89C51多出了哪个功能？___
A. 存储器加倍
B. 具有WDT工能
C. 多了一个8位输入/输出端口
D. 多了一个串行口
【单选题】
6在DIP40封装的8×51芯片里，复位RESET引脚的引脚编号是什么？___
【单选题】
7在DIP40封装的8×51芯片里，接地引脚与电源引脚的引脚编号是什么？___
A. 1、21
B. 11.31
C. 20、40
D. 19、39
【单选题】
9在12MHz始终脉冲的8051系统里，一个机器周期有多长？___
A. 1µs
B. 12µs
C. 1ms
D. 12ms
【单选题】
12下列哪个寄存器是8×51内的16位寄存器？___
【单选题】
14在8×51的输入/输出端口里，哪个输入/输出端口执行在输出功能时没有内部上拉电阻？___
【单选题】
8×51的P0采用哪种电路结构？___
A. 集电极开路式输出
B. 基极开路式输出
C. 发射机开路式输出
D. 图腾柱输出
【单选题】
17在8×51里，若要扩展外部存储器时，数据总线连接哪个输入/输出端口？___
【单选题】
点亮一般的LED所耗用的电流约为多少？___
A. 1~5µA
B. 10~20µA
C. 1~5mA
D. 10~20mA
【单选题】
19一般地，蜂鸣器属于哪种负载？___
A. 电阻性负载
B. 电感性负载
C. 电容性负载
D. 不导电负载
【单选题】
7405/7406的输出采用哪种电路结构？___
A. 集电极开路式输出
B. 基极开路式输出
C. 发射机开路式输出
D. 图腾柱输出
【单选题】
21在继电器中，NO接点是一种什么接点？___
A. 不使用接点
B. 不存在接点
C. 激磁后即开路的接点
D. 常开接点
【单选题】
22所谓2P的继电器，代表什么意思？___
A. 只有2个接点
B. 两相的负载
C. 两组电源
D. 2组c接点
【单选题】
23共阳极七段数码管显示器的驱动信号有何特色？___
A. 低电平点亮
B. 低电平不亮
C. 高电平点亮
D. 以上皆非
【单选题】
24在8×51的程序里，若要将某个输入/输出端口设置成输入功能，应如何处理？___
A. 先输出高电平到该输入/输出端口
B. 先输出低电平到该输入/输出端口
C. 先读取该输入/输出端口的状态
D. 先保存该输入/输出端口的状态
【单选题】
8×51提供几个外部中断和定时器/计数器中断？___
A. 2,2
B. 3,6
C. 2,3
D. 3,7
【单选题】
8×51的IP缓存器的功能如何？___
A. 设置中断优先级
B. 启动中断功能
C. 设置中断触发信号
D. 定义CPU的网址
【单选题】
28若要让采用低电平触发，则应如何设置？___
A. EX0=0
B. EX0=1
C. IT0=0
D. IT0=1
【单选题】
29在Keil µVision3里进行调试/仿真时，在哪里操作才能触动程序中断？___
A. 在Interrupt System
B. 在Cotorl Box对话框里
C. 直接单击魔术棒按钮即可
D. 直接按0键
【单选题】
30在8×51所提供的中断功能里，下列哪个优先级比较高？___
A. T1
B. RI/TI
C. T0
D. INT0
【单选题】
31在TCON缓存里，IE1的功能是什么？___
A. 触发 IE1中断
B. 指示IE1中断的标志
C. 提高IE1优先等级
D. 取消IE1中断
【单选题】
32在Keil C里，中断子程序与函数又何不同？___
A. 中断子程序不必声明
B. 函数不必声明
C. 中断子程序必须有形式参数
D. 中断子程序一定会有返回值
【单选题】
33若要同时启用INT0及INT1中断功能，则应如何设置？___
A. TCON=0×81
B. IE=0×85
C. IP=0×83
D. IE=0×03
【单选题】
35在8×51的Timer里，若使用Mode 0，其最大计数值为多少个机器周期？___
A. 65636
B. 8192
C. 1024
D. 256
【单选题】
36在12MHz的8×51系统里，哪一种方式一次可定时5ms？___
A. Mode 0及Mode 1
B. Mode 1及Mode 2
C. Mode 2及Mode 3
D. Mode3及Mode 1
【单选题】
37若要让Timer作为外部计数只用，应如何设置？___
A. Gate=0
B. Gate=1
C. C/=0
D. C/=1
【单选题】
39下列哪个不是8×51所提供的省电方式？___
A. PD方式
B. IDL方式
C. LP方式
D. 待机方式
【单选题】
89S51的看门狗有何作用？___
A. 重复执行程序
B. 找回遗失数据
C. 复位系统
D. 防止中毒
【单选题】
41若要启用WDT，则应依次填入WDTRST寄存器哪些数据？___
A. 0xe1、0xe2
B. 0xe1、0x1e
C. 0x1e、0xe1
D. 0x10、0x01
【单选题】
8×51的定时器，在下列哪种方式下具有自动加载功能？___
A. Mode0
B. Mode1
C. Mode2
D. Mode3
【单选题】
45下列哪种AD转换器的转换速度比较快？___
A. 双斜率型AD转换器
B. 比较型AD转换器
C. 连续计数式AD转换器
D. 逐渐接近式AD转换器
【单选题】
46下列哪种AD转换器的精密度比较高？___
A. 双斜率型AD转换器
B. 比较型AD转换器
C. 连续计数式AD转换器
D. 逐步逼近式AD转换器
【单选题】
47对于8×8 LED点阵而言，其中的LED个数及引脚各为多少？___
A. 64、16
B. 16、16
C. 64、12
D. 32、12
【单选题】
48在共阳极型8×8 LED点阵里，其阳极如何连接？___
A. 各行阳极连接到行引脚
B. 各列阳极连接到列引脚
C. 各行阳极连接到列引脚
D. 各列阳极连接到行引脚
【单选题】
49在共阳极型8×8 LED点阵里，其阴极如何连接？___
A. 各行阴极连接到行引脚
B. 各列阴极连接到列引脚
C. 各行阴极连接到列引脚
D. 各列阴极连接到行引脚
【单选题】
50双色8×8 LED点阵的列引脚与行引脚各位多少？___
A. 12、12
B. 8、16
C. 16、8
D. 24、8
【单选题】
___的方向规定由高电位点指向低电位点。
【单选题】
三相电动势到达最大的顺序是不同的，这种达到最大值的先后次序，称三相电源的相序，相序为U-V-W-U，称为___。
【单选题】
电路的作用是实现能量的传输和转换、信号的___和处理。
【单选题】
电阻器反映导体对电流起阻碍作用的大小，简称___。
A. 电动势
B. 功率
C. 电阻率
D. 电阻
推荐试题
【单选题】
Which scenario shows a reason for VMware Tools failing to install? ___
A. Virtual machine has a CD-ROM configured.
B. Guest OS Antivirus is blocking the VMware Tools installation.
C. Guest OS has 64-bit ldd (list dynamic dependencies) utility installed.
D. Virtual machine is powered on.
【单选题】
An administrator is configuring an ESXi 6.x host to use multiple NICs to resolve a management network redundancy error. After configuring a second NIC, the server is not able to communicate when the primary connection is taken down. The administrator analyzes the Exhibit shown here. Based on the exhibit, what is the likely cause of the issue? ___
A. vmnic4 is not attached to a vSwitch.
B. vmnic2 is not connected to a physical switch.
C. E1000 is the incorrect NIC
D. river for this card.
【单选题】
What information is required as part of an interactive ESXi 6.x installation? ___
A. Keyboard layout
B. IP Address
C. Root password
D. DNS information
【单选题】
What is the default load balancing policy for a newly created VMkernel port on a vSphere Distributed Switch? ___
A. Route based on orginating virtual port ID
B. Route based on IP Hash
C. Route based on source mac address
D. Route based on physical NIC load
【单选题】
An administrator deploys vCenter Server using the embedded Platform Services Controller. After testing the deployment for a couple of months, it is determined that the environment would be better served with an external Platform Services Controller. What should the administrator do to meet this new requirement? ___
A. Deploy a fresh instance of vCenter Server with an external Platform Services Controller.
B. Perform a fresh install of an external Platform Services Controller.
C. Migrate the embedded Platform Services Controller to an external Platform Services Controller.
D. Upgrade the embedded Platform Services Controller to an external Platform Services Controller.
【单选题】
Why are some virtual machines orphaned after rebooting a High Availability (HA) enabled host? ___
A. The Orphaned virtual machines have HA restart disabled.
B. The Orphaned virtual machines moved recently and the change did not persist.
C. The host is attached to failed storage.
D. The host just came out of maintenance mode.
【单选题】
Which vSphere 6 Standard Edition feature will allow an organization to ensure that critical multi-threaded applications have the maximum possible uptime? ___
A. Fault Tolerance
B. High Availability
C. Distributed Resource Scheduler
D. App HA
【多选题】
An application running in a virtual machine is experiencing performance issues. When utilizing performance monitoring utilities, it is noted that the CPU Utilization of the application is at 100%. Which two scenarios are probable causes of the CPU contention for the application? (Choose two.)___
A. There is a network I/O constraint.
B. There is a storage I/O constraint.
C. There is insufficient disk space assigned to the virtual machine.
D. The application is not virtualization aware.
【多选题】
A Fault Tolerance (FT) virtual machine with four vCPUs is experiencing high latency when performing ICMP and Application tests. What are three potential causes that may be attributing to this latency? (Choose three.)___
A. The FT network has insufficient bandwidth and is running on a 1GB Link.
B. The FT network is on a particularly high latency link.
C. The FT network has been configured with Network I/O Control.
D. The FT virtual machine is running an e1000 network adapter.
E. The
F. T virtual machine is running on poor performing network-based storage.
【多选题】
A virtual machine is experiencing performance issues. The following performance metrics are observed: <CPU usage value for the virtual machine is above 90%> < CPU ready value for the virtual machine is above 20%> Which two activities will likely resolve the performance issues? (Choose two.)___
A. Set a CPU reservation for the virtual machine.
B. Increase the CPU limit on the virtual machine.
C. Decrease CPU shares equally for all virtual machines on the host.
D. Increase CPU shares equally for all virtual machines on the host.
【多选题】
An administrator is upgrading a vSphere Distributed Switch. The existing switch is version 6.0 and the administrator wants to upgrade to the latest version possible. The environment contains several ESXi 6.1 hosts. Which two options are available to ensure that the upgraded switch will be compatible with these hosts? (Choose two.)___
A. Upgrade the vSphere Distributed Switch to 6.0
B. Upgrade the ESXi 5.5 hosts to version 6.0, then upgrade the vSphere Distributed Switch to 5.5
C. Upgrade the vSphere Distributed Switch to 5.1
D. Upgrade the
E. SXi host switches to 5.5, then upgrade the vSphere Distributed Switch to 5.5
【多选题】
An administrator attempts to create a Thick Provisioned Virtual Disk (VMDK) on an NFS datastore; but it fails. Which two reasons would explain the failure? (Choose two.)___
A. Datastore is on an NFS 3 storage server that does not support Hardware Acceleration
B. Datastore is on an NFS 4.1 storage server
C. Only VMFS datastores support "Thick Provisioned" VMDK
D. The NFS datastore was not created on a "Thick Provisioned" device
【多选题】
Which two NFS Protocol versions does vSphere 6 support? (Choose two.)___
A. Version 3
B. Version 3.1
C. Version 4
D. Version 4.1
【多选题】
Which three operations occur during a cold migration of a virtual machine? (Choose three.)___
A. The virtual machine disks are moved if the datastore is being changed.
B. The virtual machine is registered with the destination server.
C. The source virtual machine is removed from the old hosts.
D. The virtual machine hardware is upgraded.
E. The virtual machine files are quiesced prior to the migration.
【多选题】
A 4 GB Memory virtual machine is experiencing extended memory issues, as shown in the Exhibit. What potential issues could be attributed to this memory pressure?___
A. A limit is imposed on the virtual memory of this virtual machine.
B. The Balloon driver has been uninstalled.
C. A limit has been imposed on the Virtual CPU of the virtual machine.
D. Storage IO control has been enabled for the virtual machine causing the swapped memory.
【多选题】
You are creating a virtual machine in the Web Client using the New Virtual Machine wizard. Which two steps are required? (Choose two.)___
A. Select a valid name.
B. Select a cluster for the compute resource.
C. Select a network adapter.
D. Select the virtual machine compatibility.
【多选题】
An administrator has been given requirements to configure vMotion for a new virtual machine. The configuration should: <Provide Network Redundancy Use VLAN 550> <Be secured against anyone trying to spoof communication The vSwitch1 configuration is shown in the Exhibit.> Which three changes should be made to meet the stated requirements? (Choose three.)___
A. The VLAN ID must be set appropriately.
B. The default values for MAC Address Changes and Forged Transmits must be altered.
C. The teaming and failover adapters must be set appropriately.
D. The Traffic Shaping configuration must be altered.
E. The Load Balancing Policy must be set appropriately.
【多选题】
Which three traffic types are available services options when configuring a vmkernel port? (Choose three.)___
A. Provisioning Traffic
B. Virtual Volumes Traffic
C. vSphere Replication NFC Traffic
D. Virtual SAN Traffic
E. FCoE Traffic
【多选题】
An administrator logs into the vSphere Web Client, but is unable to see any hosts and clusters. Which two options could fix the problem? (Choose two.)___
A. Verify that the client web browser and vCenter Server are in the same broadcast domain.
B. Verify that the vCenter Server system is registered with the same Platform Services Controller as the vSphere Web Client.
C. Log in to the vCenter Server as a user within the Active
D. irectory domain.
【多选题】
Which three VLAN Tagging modes are available in vSphere 6.x? (Choose three.)___
A. External Switch Tagging
B. Private VLAN Tagging
C. Virtual Switch Tagging
D. VXLAN Tagging
E. Virtual Guest Tagging
【多选题】
Which two statements are true about VMFS5 datastores on ESXi 6.x? (Choose two.)___
A. Virtual Disk (VMDK) size can be larger than 2TB.
B. Datastore extent size can be larger than 2TB.
C. Only Physical Mode Raw
D. evice Map (Passthrough-RDM) can be larger than 2TB.
【多选题】
Which two statements are correct when turning off a Distributed Resource Scheduler (DRS) Cluster? (Choose two.)___
A. The resource pool hierarchy of the DRS cluster is maintained.
B. The resource pool hierarchy of the DRS cluster is removed.
C. The affinity settings of the
D. RS cluster are removed and not maintained when DRS is re-enabled.
【多选题】
An administrator is creating a new Virtual SAN cluster on a Layer 2 network. There is an existing Virtual SAN cluster on the same Layer 2 network. Which two actions would allow the new Virtual SAN cluster to coexist with the older cluster? (Choose two.)___
A. Change the default Multicast Address on the new Virtual SAN cluster.
B. Change the default Unicast Address on the new Virtual SAN Cluster.
C. Create a separate VLAN for each cluster.
D. Create an ARP Alias for the Virtual SAN VMkernel Network Adapter.
【多选题】
A vCenter Operations Manager 5.7 environment is upgraded to vRealize Operations. After the upgrade, the analytics services fail to start. Which three steps must be taken to resolve the problem? (Choose three.)___
A. Take the vRealize Operations cluster offline.
B. Delete the activity persistence files.
C. Bring the cluster back online.
D. Remove any unresponsive nodes.
E. Stop the CaSA service.
【多选题】
An organization has an ESXi 6.x host that contains two resource pools. The host is being relocated to a DRS cluster. What two actions can be taken to integrate the host into the cluster, and what would happen to the existing ESXi resource pool hierarchy as a result? (Choose two.)___
A. Place all of the host's virtual machines into the DRS cluster root resource pool. The resource pools present on the host will be deleted.
B. Create a resource pool for the ESXi host's virtual machines and resource pools. The resource pools present on the host will be deleted.
C. Place all of the host's virtual machines into the DRS cluster root resource pool. The resource pools present on the host will be preserved.
D. Create a resource pool for the
E. SXi host's virtual machines and resource pools. The resource pools present on the host will be preserved.
【多选题】
Which two parameters are required when adding an iSCSI target to an iSCSI Software Adapter using Dynamic Discovery? (Choose two.)___
A. The iSCSI device's IP Address or Fully Qualified Domain Name
B. The Port Number
C. The iSCSI device's iSCSI Qualified Name (IQN)
D. The Default Gateway IP Address
【多选题】
Which two SMTP Notification Event Details are specific to alarms triggered by events? (Choose two.)___
A. User Name
B. Summary
C. Old Status
D. Target
【多选题】
Which two High Availability ___ Cluster admission control policies can help avoid resource fragmentation? (Choose two.)(AC)
A. Define failover capacity by static number of hosts
B. Define failover capacity by reserving a percentage of the cluster resources
C. Use dedicated failover hosts
D. Use Virtual Machine Monitoring
【多选题】
An attempt to enable vSphere Fault Tolerance for a powered-on virtual machine fails. Which two scenarios would result in this failure? (Choose two.)___
A. The virtual machine has three vCPUs configured.
B. The host on which the virtual machine is running has insufficient memory resources.
C. The virtual machine has insufficient resources to accommodate full reservation plus the overhead memory.
D. VMware High Availability is enabled on the cluster of which this host is a member.
【多选题】
A vApp template recently added to a Content Library is not displayed. Which two actions could correct this problem? (Choose two.)___
A. Manually synchronize the library
B. Select the Download all library content immediately option
C. Select the Sync subscribed library option
D. Manually download the vApp template
【多选题】
What are three valid disk configurations for the vSphere Data Protection 6.x Appliance? (Choose three.)___
A. 500GB
B. 1TB
C. 1.5TB
D. 2TB
E. 4TB
【多选题】
Which three connection types are available when configuring a vSwitch in the vSphere Web Client? (Choose three.)___
A. VMkernel Network Adapter
B. Physical Network Adapter
C. Virtual Machine Port Group for a Standard Switch
D. vMotion Network Adapter
E. vSAN Network Adapter
【多选题】
Which three features can be enabled for a new host cluster? (Choose three.)___
A. Storage Distributed Resource Scheduling
B. High Availability
C. Fault Tolerance
D. Distributed Resource Scheduling
E. Virtual SAN
【多选题】
An administrator receives a report that no real time statistics are available for a virtual machine in the vCenter Server inventory. Which two statements indicate likely causes of the problem? (Choose two.)___
A. The virtual machine is powered off.
B. The host containing the virtual machine is disconnected from vCenter Server.
C. There is insufficient real time data to display the information.
D. The vCenter Server service is not running.
【多选题】
Your manager has given you a bash script that retrieves data for ESXi 6.x host configurations. This data needs to be collected right after the installation of a host and must be run directly on the host. Which two actions can be used to run this script on an ESXi host? (Choose two.)___
A. Connect to the host with Ruby vSphere Console and run the script from there.
B. Enable SSH access from the Direct Console User Interface.
C. Enable the ESXi Shell from the
D. irect Console User Interface.
【多选题】
Which two are true about the Risk badge in vRealize Operations? (Choose two.)___
A. The Risk badge indicates potential future problems that may degrade the performance of the system.
B. Risks may require attention in the near future.
C. The Risk badge indicates problems that are degrading performance of the system.
D. Risks require attention now to correct system performance problems.
【多选题】
vSphere Update Manager allows which two virtual machine attributes to be upgraded? (Choose two.)___
A. Virtual machine firewall policies for NSX.
B. Software Packages in the virtual machine.
C. Virtual machine Hardware Version.
D. VMware Tools Upgrade.
【多选题】
What are two benefits of using NFS 4.1 with vSphere 6.x as compared to NFS 3? (Choose two.)___
A. NFS 4.1 supports Kerberos Authentication
B. NFS 4.1 supports multipathing
C. NFS 4.1 supports IPv6
D. NFS 4.1 supports hardware acceleration
【多选题】
Which three statements are true regarding Fault Tolerance? (Choose three.)___
A. Applications need to be continuously available to users.
B. Applications without native clustering capabilities can be protected.
C. Custom clustering solutions are complicated to configure and maintain.
D. Applications that have 16 vCPUs are supported.
E. Prevents application crashes by analyzing the workload and correcting problems.
【多选题】
Which two statements are true regarding VMware vSphere Flash Read Cache (vFRC)? (Choose two.)___
A. Cache fills and cache evictions happen in the granularity of a cache block size.
B. vFRC caches data from both read and write I/Os, but write I/Os are always serviced by the underlying storage.
C. vFRC caches data from both read and write I/Os, but write I/Os are always serviced by the underlying cache data.
D. Cache fills and cache evictions happen in the granularity of the disk block size.
