LPC812 PWM

题：LPC812 输出两路2Mhz PWM方波，死区时间<50ns.

系统时钟设置30Mhz(MSEL = 00100b, PSEL = 01b); The SCTimer clock set to equal system clock, so the PWM period should be 15 clk period, i.e. Tpwm = 30/2 = 15; and then each PWM pulse width is half:

LPC_SCT->MATCH[0].L = 15; // match on (half) PWM period
LPC_SCT->MATCHREL[0].L = 15;
LPC_SCT->MATCH[1].L = 6; // match on duty cycle 1
LPC_SCT->MATCHREL[1].L = 6;
LPC_SCT->MATCH[2].L = 8; // match on duty cycle 2
LPC_SCT->MATCHREL[2].L = 8;

There are also an ABORT pin which could be use as a brake function. But I do not use this function and I do not configure this pin. The finally code as below:

/* Generic Initialization */
SystemCoreClockUpdate();

LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 8); // enable the SCT clock

LPC_SWM->PINASSIGN[6] = 0x07FFFFFF;//p0.7
LPC_SWM->PINASSIGN[7] = 0xFFFFFF06; //p0.6

LPC_SCT->CONFIG |= (1 << 17); // split timers, auto limit
// LPC_SCT->CTRL_L |= (SystemCoreClock/10000000-1) << 5; // configure SCT1 as BIDIR
LPC_SCT->CTRL_L |= (1 << 4); // configure SCT1 as BIDIR

LPC_SCT->MATCH[0].L = 15; // match on (half) PWM period
LPC_SCT->MATCHREL[0].L = 15;
LPC_SCT->MATCH[1].L = 6; // match on duty cycle 1
LPC_SCT->MATCHREL[1].L = 6;
LPC_SCT->MATCH[2].L = 8; // match on duty cycle 2
LPC_SCT->MATCHREL[2].L = 8;

//simple function of pwm with deadtime
LPC_SCT->EV[0].STATE = 0xFFFFFFFF; // event 2 happens in all states
LPC_SCT->EV[0].CTRL = (1 << 0) | (1 << 12); // match 1 (DC1) only condition

LPC_SCT->EV[1].STATE = 0xFFFFFFFF; // event 3 happens in all states
LPC_SCT->EV[1].CTRL = (2 << 0) | (1 << 12); // match 2 (DC2) only condition

LPC_SCT->OUT[0].SET = (1 << 0); // event 0 set OUT0 (blue LED)
LPC_SCT->OUT[0].CLR = (1 << 0); // event 0 clears OUT0 (blue LED)

LPC_SCT->OUT[1].SET = (1 << 1); // event 1 sets OUT1 (red LED)
LPC_SCT->OUT[1].CLR = (1 << 1); // event 1 clear OUT1 (red LED)

LPC_SCT->RES |= 0x0000000F; // toggle OUT0 and OUT1 on conflict
LPC_SCT->OUTPUT |= 1; // default set OUT0 and clear OUT1

LPC_SCT->CTRL_L &= ~(1 << 2); // start timer

OR LIKE THIS:

/* Generic Initialization */
SystemCoreClockUpdate();

LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 8); // enable the SCT clock

LPC_SWM->PINASSIGN[6] = 0x07FFFFFF;//p0.7
LPC_SWM->PINASSIGN[7] = 0xFFFFFF06; //p0.6

LPC_SCT->CONFIG |= (1 << 17); // split timers, auto limit
LPC_SCT->CTRL_L |= (1 << 4); // configure SCT1 as BIDIR

LPC_SCT->MATCH[0].L = 15; // match on (half) PWM period
LPC_SCT->MATCHREL[0].L = 15;
LPC_SCT->MATCH[1].L = 6; // match on duty cycle 1
LPC_SCT->MATCHREL[1].L = 6;
LPC_SCT->MATCH[2].L = 8; // match on duty cycle 2
LPC_SCT->MATCHREL[2].L = 8;

//full function of pwm with deadtime
LPC_SCT->EV[0].STATE = 0xFFFFFFFF; // event 0 happens in all states
LPC_SCT->EV[0].CTRL = (2 << 10) | (2 << 12); // IN_0 falling edge only condition

LPC_SCT->EV[1].STATE = 0xFFFFFFFF; // event 1 happens in all states
LPC_SCT->EV[1].CTRL = (1 << 10) | (2 << 12); // IN_0 rising edge only condition

LPC_SCT->EV[2].STATE = 0xFFFFFFFF; // event 2 happens in all states
LPC_SCT->EV[2].CTRL = (1 << 0) | (1 << 12); // match 1 (DC1) only condition

LPC_SCT->EV[3].STATE = 0xFFFFFFFF; // event 3 happens in all states
LPC_SCT->EV[3].CTRL = (2 << 0) | (1 << 12); // match 2 (DC2) only condition

LPC_SCT->OUT[0].SET = (1 << 0) | (1 << 2); // event 0 and 2 set OUT0 (blue LED)
LPC_SCT->OUT[0].CLR = (1 << 2); // event 2 clears OUT0 (blue LED)

LPC_SCT->OUT[1].SET = (1 << 3); // event 3 sets OUT1 (red LED)
LPC_SCT->OUT[1].CLR = (1 << 0) | (1 << 3); // event 0 and 3 clear OUT1 (red LED)

LPC_SCT->RES |= 0x0000000F; // toggle OUT0 and OUT1 on conflict
LPC_SCT->OUTPUT |= 1; // default set OUT0 and clear OUT1

LPC_SCT->STOP_L = (1 << 0); // event 0 will stop the timer
LPC_SCT->EVEN = (1 << 1); // event 1 will generate an irq

NVIC_EnableIRQ(SCT_IRQn); // enable SCTx interrupt
LPC_SCT->CTRL_L &= ~(1 << 2); // start timer

Work finish! The result as the picture below:

LPC812 PWM相关推荐

RTT设备与驱动之PWM
这里将PWM当成一个设备:PWM简介上图是一个简单的 PWM 原理示意图,假定定时器工作模式为向上计数,当计数值小于阈值时,则输出一种电平状态,比如高电平,当计数值大于阈值时则输出相反的电平状态,比 ...
51单片机小车 L298N pwm调速串口控制按键控制
难点:1.串口定时器T1,和T0定时器优先级 2.pwm频率与占空比的设置按键控制按键1--前进按键2--后退按键3--加速按键4--减速 (板子上只有四个按键) 串口控制 '1'--前进 ...
【转载】 stm32之PWM
发现这位博主的博客被大量的转发,我也转载一篇,谁叫人家写的好呢. 原文地址:http://blog.sina.com.cn/s/blog_49cb42490100s6uh.html 脉冲宽度调制(PW ...
开关电源三种控制模式：PWM/PFM/PSM
1. PWM/PFM/PSM 三种控制模式的定义通常来说﹐开关电源(DC-DC)有三种最常见的调制方式分别为: 脉冲宽度调制(PWM) 脉冲频率调制(PFM) 脉冲跨周期调制(PSM) 在功率集成电 ...
使用 RPI.GPIO 模块的脉宽调制（PWM）功能
脉宽调制(PWM)是指用微处理器的数字输出来对模拟电路进行控制,是一种对模拟信号电平进行数字编码的方法.在树莓派上,可以通过对GPIO的编程来实现PWM. 创建一个 PWM 实例: p = GPIO. ...
树莓派c语言输出pwm波,树莓派硬件PWM输出程序
一:实验现象对于树莓派硬件PWM只有1号引脚(wiringPi),单独测试该引脚时,可以输出不同占空比控制led灯成呼吸灯的效果二:程序步骤 1,初始化wiringPi的库函数; 2,设置对应的P ...
linux pwm控制蜂鸣器滴滴_兴安盟KOBISHI电磁蜂鸣器BZ-21BLAC24V保证
兴安盟KOBISHI电磁蜂鸣器BZ-21BLAC24V保证日本KOBISHI蜂鸣器.jjb器 .蜂鸣器BZ-35VR DC24V.济南千斗工业出售,货期短.价格低.保证这里只对必须用1/2duty的 ...
全程pwm调光_dc调光的手机有哪些
dc调光的手机有哪些?目前已经发布的黑鲨游戏手机2.黑鲨游戏手机Helo均为全程DC调光,魅族16系列手机,OPPO的Reno,一加7等手机已经是支持DC调光. dc调光的手机有哪些 1.据悉,目前已 ...
cubemx pwm dma_红米K30S至尊纪念版翻车？被曝虽是LDC屏，却是PWM调光
↑↑↑击上方"蓝字"关注,每天推送最新科技新闻红米发布了自家新款性价比机型红米K30S至尊纪念版,这款产品搭载了高通骁龙865处理器,同时价格仅需2299元,而且还搭载的是LCD ...

LPC812 PWM

LPC812 PWM相关推荐

最新文章

热门文章