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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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T his article introduces how to create a custom board MCUXpresso SDK and how to use it, mainly includes three parts: Part1: Generating a Board Support Configuration (.mex) Part2: Create a Custom Board SDK Using the Board SDK Wizard Part3. Using the Custom SDK to Create a New Project   Requirements: MCUXpresso IDE v11.1.1, MCUXpresso SDK for LPC845, LPC845-BRK board. This method works for all NXP mcu which support by MCUXpresso SDK. About detail steps, please refer to attachment. Thanks!
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Hi: Since LPC series ADC has sequence function, so implement multi-channel ADC transfer is easy. But use DMA is also meaning, so there are two demos to show how to use such applications 1.lpc_multi-channels_adc_dma_sw_trg Use SW trigger multi channels ADC transfer, but use DMA to transfer result to result array. use don't need to care the channel result register, but fetch data from global data register; 2.lpc_multi-channels_adc_dma_hw_trg for many cases, user need to trigger ADC multi channels transfer periodly, and collect enough data for processing. so this demo use SCT_OUT7 to trigger ADC Sequence A for 6 channels, then after 1024 rounds, generate DMA interrupt to process all 6*1024 data array. all demos are implemented on SDK2.6.0 
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Recently I found some customers have a bit of problem when porting project from one MCU to another, so this article using simple steps demonstrates how to change MCU with MCUXpresso. There is also a video demonstrated the detail steps in attachment. Pay attention, as MCUXpresso User Guide says: All projects are associated with a particular MCU at creation time. The target MCU determines the project memory layout, startup code, LinkServer flash driver, libraries, supporting sources,launch configuration options etc. etc. so changing a project’s associated MCU should not be undertaken unless you have a total grasp of the consequence of this change. Therefore rather than changing a project’s associated MCU, it is strongly recommended that instead a new project is generated for the desired MCU and this new project is edited as required. However, on occasion it may be expedient to reset a project’s MCU (and associated SDK) and this can be achieved as follows. For example, changing lpc55s69 to lpc55s06, we need install SDKs for lpc55s69 and lpc55s06 before all the below steps. 1 - Change MCU & Package 1.1 – Change MCU Right click “MCU” under Project tree, choose “Edit MCU” Uncheck ”Preserve memory configuration”(it is checked by default)->choose LPC55S06->there is a warning, choose Yes. We can see the Memory details changed to lpc55s06, then click ”Apply and close”. 1.2 – Change Package 2 - Change Compiler Definitions In Properties view->Settings->MCU Compiler ->Preprocessor, change the definition for CPU from LPC55S69JBD100 to LPC55S06JBD64 as below: 3 – Change/add SDK driver for LPC55s06 Selected project, then click ”Manage SDK components”, choose the drivers our application used, for example, clock, power, usart. Click “OK”, then click “Yes” to update. Delete LPC55S69 device related files: Add “system_LPC55S06.c” and “system_LPC55S06.h” files: 4 - Change startup file. Delete LPC55s69 startup files, add “startup_lpc55s06.c”, we can find the startup file in any SDK demo. 5 - Change board related files. Refer to our own new board, change files under “board” folder, for example pins, uart number, here directly copy from SDK demo for LPCxpresso55s06 board. 6 - Test the project  function with new board Build project until no compile error, download and run it, result as below.        
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LPC: Regarding to Internal Clock Calibration In MCU development, using the internal crystal oscillator as a clock source instead of the external crystal oscillator can save costs. But the clock frequency generated by the internal crystal oscillator is affected by temperature and MCU frequency more than external crystal oscillator. Many customers have questions about the internal clock accuracy, whether the internal clock can be used for USB transmission, and how to calibrate the internal clock. This article mainly explains this. 1. Calibrate internal clock by FREQTRIM Normally, we can only calibrate the internal clock by adjusting the FREQTRIM value. The internal clock frequency is affected by temperature, MCU frequency and other factors. The FRO control register can calibrate the internal clock, as follows:   The FREQTRIM register value ranges from 0 to 255, and each adjustment step is about 0.1% of the internal clock frequency. There is no precise formula to express the relationship between the FREQTRIM value and the FRO frequency. The ideal FREQTRIM value can only be determined by adjusting FREQTRIM in code and observing FRO output waveform with oscilloscope. Test and observation: The following is the test result. It shows how FRO frequency varies with FREQTRIM increasing from 0-255. Test result of first development board:     Test result of second development board:   The following two points can be seen from test results: - There is no linear relationship between the FRO clock frequency and the FREQTRIM register value, and there is no precise formula to express the relationship between them; - Even for chips of the same part number, the internal clock frequency changes are slightly different, with the FREQTRIM register value changing, but the trend is same. Therefore, there is no precise formula to guide internal clock frequency calibration. You can only adjust the FREQTRIM register value repeatedly, just like adjusting the focus of a projector. Use an oscilloscope to check the frequency of the internal clock pin to find the most suitable FREQTRIM register value. There is same solution for FRO clock frequency calibration about other LPC chips.   2. LPC51U68: Software calibration USB transmission when using internal clock source The Full Speed USB module of LPC51U68 has a unique FRO automatic calibration function, which automatically adjusts the FREQTRIM value to achieve FRO calibration by measuring the USB SOF bit. Once FRO is calibrated, the corresponding system clock and peripheral clock are calibrated. This solution is only applicable to LPC51U68, please refer to the user manual for other chips. The following is the FRO clock accuracy described in LPC51U68 User Manual, which is ± 1%:   For Full Speed USB, the USB data transmission accuracy requirement is ±0.25%, and the FRO clock accuracy is not satisfied. NXP provides a software solution to calibrate FRO by measuring the first packet of frame (SOF), which can meet the transmission accuracy in Full Speed mode.   The solution download link is as follows: https://www.nxp.com/docs/en/application-note/TN00035.zip  
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Recently, customers reported that the number of PWM generated by SCTimer module was inconsistent between LPC55s06 user manual and data sheet. There are many kinds of PWM generation formats, so the maximum number of PWM generated by SCTimer is also different. I think the user manual and data sheet are not very clear, so this paper makes a specific analysis. It mainly depends on SCTimer resources, such as the number of events and output channels. For all LPC series, the mechanism of SCTimer generating PWM is the same. Therefore, this paper takes LPC55s6 as an example. LPC55s06 user manual: The SCTimer/PWM supports: – Eight inputs. – Ten outputs. – Sixteen match/capture registers. – Sixteen events. – Thirty two states. According to the different control modes of generating PWM wave, this paper is divided into single-edge PWM control, dual-edge PWM control and center-aligned PWM control. 1. Single-edge PWM control The figure below shows two single-edge control PWM waves with different duty cycles and the same PWM cycle length.   It can be seen from the above figure that the two PWM waves require three events: when the counter reaches 41, 65 and 100 respectively. Because of the same PWM cycle length, all PWM outputs need only one period event. Summary: The cycle length of all PWM waves are the same, so only one period event is required. The duty cycles of each PWM are different, and each PWM requires an event. The SCTimer of LPC55s06 has 16 events, one is used as PWM period event, and there are 15 left. Theoretically, 15 channels of PWM can be generated. However, LPC55s06 has only 10 outputs, so it can generate up to 10 single-edge control PWM waves. 2. Dual-edge PWM control The figure below shows three Dual-edge control PWM waves with different duty cycles and the same PWM cycle length.   It can be seen from the above figure that the three PWM waves require seven events: when the counter reaches 1, 27, 41, 53, 65, 78, 100.   Summary: PWM cycle length control needs one event, and each PWM duty cycle needs two events to trigger. The SCTimer of LPC55s06 has 16 events, one as PWM frequency event, and the remaining 15, so it can generate up to 7 dual-edge control PWM waves. 3. Center-aligned PWM control Center-aligned PWM control is a special case of dual-edge PWM control. The figure below shows two center-aligned PWM waves with different duty cycles and the same PWM duty length.   It can be seen from the above figure that the two center-aligned PWM waves need three events in total, which are the PWM cycle length and the duty cycle trigger of the two PWM waves. Because the left and right are symmetrical, only one event is needed to control the duty cycle of one PWM. Summary: All PWM have the same cycle length, so an event is required. The duty cycle of each PWM circuit is different, but the left and right are symmetrical, and an event trigger is required for each circuit. The SCTimer of LPC55s06 has 16 events, one is used as PWM cycle length, and there are 15 left. Theoretically, 15 channels of PWM can be generated, but LPC55s06 has only 10 outputs, so it can generate up to 10 channels of unilateral control PWM wave. Summary:   Maximum number of PWM generated by LPC55s6 SCTimer: Single-edge PWM control : 10 Dual-edge PWM control : 7 Center-aligned control: 10   The number of SCTimer events and output channels is different with different chips, but the analysis method is the same. Customers can analyze whether the SCTimer in a certain chip meets the requirements.
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Contents 1. Principle of energy measurement 2. Energy measurement test   2.1 Use in non-Debug state   2.2 Use in Debug state   During the operation of MCU, real-time measurement of board current and voltage is of great significance to the stability of system power consumption. Especially in scenarios that are sensitive to voltage and current fluctuations, it is particularly important to collect and analyze high-frequency samples. MCUXpresso IDE integrates the power measurement function, which can measure the current and voltage of the development board in real time and calculate the real-time power consumption. Based on MCUXpresso IDE v11.5.0, this article mainly explains power measurement function usage. 1.   Principle of energy measurement Currently the MCUXpresso IDE energy measurement function supports the following development boards: -LPCXpresso546x8/540xx/54S0xx -LPCXpresso54102 -LPCXpresso51U68/54114 -QN9090-DK006/ JN5189-DK006/IOTZKB-DK006 -QN9080DK The power measurement actually uses the LPC-Link2/MCU-Link debugger on the development board to collect the conversion value of the A/D conversion chip, and perform software calculation to obtain the power measurement result. Taking LPCXpresso54628 development board as an example, the following is the circuit diagram of the power measurement part: Fig.1 The MAX9634TEUK+T is a precision current amplifier. And ADC122S021 is a 12-bit A/D converter with dual-channel sampling, its rate can reach 200ksps. ADC122S021 collects LPC54xx_CURR and SHLD_CURR voltages, IDE sets Target resistor (Total Rvsense in the figure) and Shield resistor (resistance value corresponding to SHLD_CURR) in advance. The LPC-Link2 debugger can calculate the voltage, current and power consumption information by collecting AD conversion values. 2.   Energy measurement test Taking LPCXpresso54628 development board as an example. Open the menu bar : Analysis->Energy Measurement. The Energy Measurement interface will appear in the lower right corner of the screen, which is divided into Plot drawing and Config configuration interface. It can be used in Debug state or in non-Debug state during measurement. Test the case of LED small light flickering and observe the changes of voltage, current and energy consumption. Note that the LPC-Link2 debugger version should be CMSIS-DAP probe version 5.147 and above. 2.1 Use in non-Debug state Click the button  in energy measurement interface and select the measured in the config interface. You can select the target voltage, target current and shielding current. The sampling rate can be selected as 50ksps, 62.5ksps or 100ksps. First select the model of the development board to be tested, and then continue to select the target resistance and shielding resistance. The target resistance value is selected according to the jumper cap description in Figure 1. The resistance value of the shielding resistance is the fixed resistance value of development board. As shown in the figure below: Fig.2 Select the target voltage to be measured, and click the button to run the Energy Measurement interface. You can see the slight fluctuation of voltage in the plot interface and view the average voltage through the delimited area of horizontal measurement, as follows: Fig.3 Select the target current to be measured. Before measuring the target current, click Read from target on the config interface to calculate the average value of the target voltage within 0.5s for subsequent power consumption calculation. Click the run button to see that the target current fluctuates slightly with the flashing of the small light in the plot interface. At the same time, check the average current, power consumption and energy consumption through the delimited area of horizontal measurement, as follows: Fig.4 2.2 Use in Debug state When used in the debug state, you can use MCUXpresso IDE or KEIL to enter the debugging state. Click the button on the energy measurement interface to read the power consumption in the debug state. The measurement process is the same as the non-Debug state, as follows: Fig.5 This is a general enablement document of how to use energy measurement feature in debug and non-debug mode. For more, please refer  MCUXpresso_IDE_Energy_Measurement. pdf under MCUXpresso IDE install folder.    
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