LPC Microcontrollers Knowledge Base

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LPC Microcontrollers Knowledge Base

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The following document contains a list of documents, questions and discussions that are relevant in the community based on the amount of views they are receiving each month. If you are having a problem, doubt or getting started in LPC or MCUXpresso you should check the following links to see if your doubt have been already solved in the following documents and discussions. MCUXpresso MCUXpresso Supported Devices Table  FAQ: MCUXpresso Software and Tools  How to create a new LPC project using LPCOpen and MCUXpresso IDE  Introducing MCUXpresso SDK v.2 for LPC54xxx Series  Generating a downloadable MCUXpresso SDK v.2 package  Using the MCUXpresso Pins Tool   MCUXpresso Config Tools is now available!   LPC55xx Multicore Applications with MCUXpresso IDE  LPC information LPC5460x MCU Family Overview  USB with NXP Microcontrollers LWIP memory requirements  LPC800 Four-Part Webinar Series!  The LPC804 Programmable Logic Unit (PLU)   LPC84x Technical Training - Now Available Guides and Examples Flashing and Installing the new firmware and drivers for LPC11U35 debug probes  Enabling debug output  USB FLASH download, programming, and security tool (DFUSec)  DMA Ping-Pong application  Getting start with LPCXpresso54608 & emWin Graphics;  Capacitive Touch example using the LPC845 Breakout Board  OLED Display Application Example using LPC845 Breakout Board and SPI  Mixed-Signal Logic Analyzer & Oscilloscope (Lab Tool) Solution  LPC FAQ How to calculate the value of crystal load capacitors? Can I send a message with X/Y/Z bits in the ID?  What is the difference between error active and error passive? What is the sample point for?  How can I verify the configured CAN bitrate, using an oscilloscope? 
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The documentation discusses how to generate phase-shift PWM signals based on SCTimer/PWM module, the code is developed based on MCUXpresso IDE version 10.3 and LPCXpresso5411x board. The LPC family has SCTimer/PWM module and CTimer modules, both of them can generate PWM signals, but only the SCTimer/PWM module  can generate phase-shift PWM signals. In the code, only the match registers are used to generate events, I/O signals are not used.  The match0 register is set up as (SystemCoreClock/100), which determines the PWM signal frequency. The the match1 register is set up as 0x00, which generate event1. The the match2 register is set up as (SystemCoreClock/100)/2;, which generate event2. The duty cycle is (SystemCoreClock/100)/2-0x00= (SystemCoreClock/100)/2, which is 50% duty cycle, the cycle time is (SystemCoreClock/100). The event1 sets the SCT0_OUT1, event2 clears the SCT0_OUT1, so SCT0_OUT1 has 50% duty cycle. The the match3 register is set up as (SystemCoreClock/100)/4;, which generate even3. The the match4 register is set up as 3*(SystemCoreClock/100)/4, which generate event4. The duty cycle is 3*(SystemCoreClock/100)/4  -  (SystemCoreClock/100)/4= (SystemCoreClock/100)/2, which is 50% duty cycle. The event3 sets the SCT0_OUT2, event4 clears the SCT0_OUT2, so SCT0_OUT2 has 50% duty cycle. The phase shift is (SystemCoreClock/100)/4 - 0x00= (SystemCoreClock/100)/4, which corresponds 90 degree phase shift. PWM initilization code: //The SCT0_OUT1 can output PWM signal with 50 duty cycle from PIO0_8 pin //The SCT_OUT2 can output PWM signal with 50 duty cycle fron PIO0_9 pin //The SCT0_OUT1 and SCT0_OUT2 PWM signal has 90 degree phase shift. void SCT0_PWM(void) {     SYSCON->AHBCLKCTRL[1]|=(1<<2); //SET SCT0 bit     SCT0->CONFIG = (1 << 0) | (1 << 17); // unified 32-bit timer, auto limit     SCT0->SCTMATCHREL[0] = SystemCoreClock/100; // match 0 @ 100 Hz = 10 msec     SCT0->EVENT[0].STATE = 0xFFFFFFFF; // event 0 happens in all states     //set event1     SCT0->SCTMATCHREL[1]=0x00;     SCT0->EVENT[1].STATE = 0xFFFFFFFF; // event 1 happens in all states     SCT0->EVENT[1].CTRL = (1 << 12)|(1<<0); // match 1 condition only     //set event2     SCT0->SCTMATCHREL[2]=(SystemCoreClock/100)/2;     SCT0->EVENT[2].STATE = 0xFFFFFFFF; // event 2 happens in all states     SCT0->EVENT[2].CTRL = (1 << 12)|(2<<0); // match 2 condition only     //set event3     SCT0->SCTMATCHREL[3]=(SystemCoreClock/100)/4;     SCT0->EVENT[3].STATE = 0xFFFFFFFF; // event 3 happens in all states     SCT0->EVENT[3].CTRL = (1 << 12)|(3<<0); // match 3 condition only     //set event4     SCT0->SCTMATCHREL[4]=3*(SystemCoreClock/100)/4;     SCT0->EVENT[4].STATE = 0xFFFFFFFF; // event 4 happens in all states     SCT0->EVENT[4].CTRL = (1 << 12)|(4<<0); // match 4 condition only     //PWM output1 signal     SCT0->OUT[1].SET = (1 << 1); // event 1 will set SCT1_OUT0     SCT0->OUT[1].CLR = (1 << 2); // event 2 will clear SCT1_OUT0     SCT0->RES |= (3 << 2); // output 0 toggles on conflict     //PWM output2 signal     SCT0->OUT[2].SET = (1 << 3); // event 3 will set SCT1_OUT0     SCT0->OUT[2].CLR = (1 << 4); // event 4 will clear SCT1_OUT0     SCT0->RES = (3 << 4); // output 0 toggles on conflict     //PWM start     SCT0->CTRL &= ~(1 << 2); // unhalt by clearing bit 2 of the CTRL } Pin initialization code: //PIO0_8 PIO0_8 FC2_RXD_SDA_MOSI SCT0_OUT1 CTIMER0_MAT3 //PIO0_9 PIO0_9 FC2_TXD_SCL_MISO SCT0_OUT2 CTIMER3_CAP0 - FC3_CTS_SDA_SSEL0 void SCTimerPinInit(void) {     //Enable the     SCTimer clock     SYSCON->AHBCLKCTRL[0]|=(1<<13); //set IOCON bit     //SCTimer pin assignment     IOCON->PIO[0][8]=0x182;     IOCON->PIO[0][9]=0x182;     IOCON->PIO[0][10]=0x182; } Main Code: #include <stdio.h> #include "board.h" #include "peripherals.h" #include "pin_mux.h" #include "clock_config.h" #include "LPC54114_cm4.h" void SCT0_Init(void); void SCTimerPinInit(void); void P1_9_GPIO(void); void SCT0_PWM(void); int main(void) {       /* Init board hardware. */     BOARD_InitBootPins();     BOARD_InitBootClocks();     BOARD_InitBootPeripherals();     printf("Hello World\n");    // SCT0_Init();    // P1_9_GPIO();     SCTimerPinInit();     SCT0_PWM();     /* Force the counter to be placed into memory. */     volatile static int i = 0 ;     /* Enter an infinite loop, just incrementing a counter. */     while(1) {         i++ ;     }     return 0 ; } The Yellow channel is PIO0_8 pin output signal, which is SCT0_OUT1 PWM output signal. The Bule channel is PIO0_9 pin output signal, which is SCT0_OUT2 PWM output signal.
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Do you want to know more about one of our hottest products in the LPC800 series portfolio? Take a look at this technical presentation featuring the LPC84x MCU family. Based on the Arm Cortex-M0+ core, the LPC84x Family of MCUs is a low-cost, 32-bit MCU operating at frequencies of up to 30 MHz. The LPC84x MCU family supports of up to 64 KB of flash memory and 16 KB of SRAM. In addition, to make things easier, the LPC800 series McUs are supported by our free example code bundles and now, they're also supported by the MCUXpresso Software Develpment Kit (SDK).  Fig 1. LPC84x MCU Family Block Diagram
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