Chapter 13 PWM

《Chapter 13 PWM》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、Chapter13Pulse-WidthModulator(S12PWM8B8CV1)中心对齐输出模式和4个可用的时钟源该PWM模块有8个独立控制中心和左对齐输出的通道。独立控制周期、占空比、计数器。ThePWMdefinitionisbasedontheHC12PWMdefinitions.ItcontainsthebasicfeaturesfromtheHC11withsomeoftheenhancementsincorporatedontheHC12:centeralignedoutputmodeandfouravailableclocksourc

2、es.ThePWMmodulehaseightchannelswithindependentcontrolofleftandcenteralignedoutputsoneachchannel.Eachoftheeightchannelshasaprogrammableperiodanddutycycleaswellasadedicatedcounter.Aflexibleclockselectschemeallowsatotaloffourdifferentclocksourcestobeusedwiththecounters.Eachofthemodu

3、latorscancreateindependentcontinuouswaveformswithsoftware-selectabledutyratesfrom0%to100%.ThePWMoutputscanbeprogrammedasleftalignedoutputsorcenteralignedoutputs.13.1.1Features周期和占空比双缓冲在有效周期的末尾或通道被禁用，更改才会有效（PWM计数器归零）8个8位或4个16位PWM通道Fourclocksources(A,B,SA,andSB)provideforawiderange

4、offrequencies4个时钟源（A，B，SA和SB）提供了广泛的频率紧急关闭ThePWMblockincludesthesedistinctivefeatures:•EightindependentPWMchannelswithprogrammableperiodanddutycycle•DedicatedcounterforeachPWMchannel•ProgrammablePWMenable/disableforeachchannel•SoftwareselectionofPWMdutypulsepolarityforeachchannel•

5、Periodanddutycyclearedoublebuffered.Changetakeseffectwhentheendoftheeffectiveperiodisreached(PWMcounterreacheszero)orwhenthechannelisdisabled.•Programmablecenterorleftalignedoutputsonindividualchannels•Eight8-bitchannelorfour16-bitchannelPWMresolution•Fourclocksources(A,B,SA,andS

6、B)provideforawiderangeoffrequencies•Programmableclockselectlogic•Emergencyshutdown13.1.2运行模式可编程禁止时钟进入分频器，以进入低功耗的等待模式。Freeze模式中有一个软件可编程选项禁止时钟输入分频器。这对仿真是有益的Thereisasoftwareprogrammableoptionforlowpowerconsumptioninwaitmodethatdisablestheinputclocktotheprescaler.Infreezemodethereisa

7、softwareprogrammableoptiontodisabletheinputclocktotheprescaler.Thisisusefulforemulation.13.2外部信号描述 13.2ExternalSignalDescriptionThePWMmodulehasatotalof8externalpins.该PWM模块共有8外部引脚。13.2.1PWM7—PWMChannel7ThispinservesaswaveformoutputofPWMchannel7andPWM通道7作为输入的紧急关断功能13.2.1PWM7—PWMCha

8、nnel7ThispinservesaswaveformoutputofPWMc