TI中文支持网Part Number:MSP432E401Y
在官方例程adc0_singleended_multichannel_timertrigger_dmareq_MSP_EXP432E401Y 中，如果直接将srcBuffer[0]的值赋给定义的数组，最后得到的数据不是预期的。
代码如下所示，在while循环中直接将srcBuffer的值赋给a[i]，得到的结果并不是预期的值。
请问这个是什么原因，同时如果想要将缓冲区的数据读取到指定的数组当中，应该用什么样的方法。
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/******************************************************************************
* MSP432E4 Example project for ADC with multiple channel and single sequencer
* with Timer Trigger and DMA Request from ADC.
*
* Description: In this application example the ADC0 is configured for a single
* sequencer sampling 4 channels in single ended mode. The ADC is triggered by
* a timer running in periodic mode with a sampling frequency of 1 KHz. After
* the conversion is completed a DMA request is generated by the ADC Sequencer.
* The data is read by the DMA and an interrupt request to the CPU is
* generated. The CPU reads the data from the DMA buffer and re-enables the
* DMA to transfer more data.
*
*MSP432E401Y
*------------------
*/|\|PE3|<-- AIN0
*| |PE2|<-- AIN1
*--|RSTPE1|<-- AIN2
*|PE0|<-- AIN3
*||
*||
*|PA0|<--U0RX
*|PA1|-->U0TX
* Author: Amit Ashara
*******************************************************************************/
/* DriverLib Includes */
#include <ti/devices/msp432e4/driverlib/driverlib.h>
/* Standard Includes */
#include <stdint.h>
#include <stdbool.h>
/* Display Include via console */
#include "uartstdio.h"
static uint16_t srcBuffer[4];
volatile bool bgetConvStatus = false;;
/* The control table used by the uDMA controller. This table must be aligned
* to a 1024 byte boundary. */
#if defined(__ICCARM__)
#pragma data_alignment=1024
uint8_t pui8ControlTable[1024];
#elif defined(__TI_ARM__)
#pragma DATA_ALIGN(pui8ControlTable, 1024)
uint8_t pui8ControlTable[1024];
#else
uint8_t pui8ControlTable[1024] __attribute__ ((aligned(1024)));
#endif
void ADC0SS2_IRQHandler(void)
{uint32_t getIntStatus;/* Get the interrupt status from the ADC */getIntStatus = MAP_ADCIntStatusEx(ADC0_BASE, true);/* If the interrupt status for Sequencer-2 is set the* clear the status and read the data */if((getIntStatus & ADC_INT_DMA_SS2) == ADC_INT_DMA_SS2){/* Clear the ADC interrupt flag. */MAP_ADCIntClearEx(ADC0_BASE, ADC_INT_DMA_SS2);/* Reconfigure the channel control structure and enable the channel */MAP_uDMAChannelTransferSet(UDMA_CH16_ADC0_2 | UDMA_PRI_SELECT,UDMA_MODE_BASIC,(void *)&ADC0->SSFIFO2, (void *)&srcBuffer,sizeof(srcBuffer)/2);MAP_uDMAChannelEnable(UDMA_CH16_ADC0_2);/* Set conversion flag to true */bgetConvStatus = true;}
}
void ConfigureUART(uint32_t systemClock)
{/* Enable the clock to GPIO port A and UART 0 */MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);/* Configure the GPIO Port A for UART 0 */MAP_GPIOPinConfigure(GPIO_PA0_U0RX);MAP_GPIOPinConfigure(GPIO_PA1_U0TX);MAP_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);/* Configure the UART for 115200 bps 8-N-1 format */UARTStdioConfig(0, 115200, systemClock);
}
void swap(int* arr1, int* arr2, int index){int j = index;int i = 0;for(i = 0; i < 256; i++,j++){arr2[j] = arr1[i];}
}
int main(void)
{uint32_t systemClock;/* Configure the system clock for 120 MHz */systemClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN |SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480),120000000);/* Initialize serial console */ConfigureUART(systemClock);/* Enable the clock to GPIO Port E and wait for it to be ready */MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);while(!(MAP_SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOE))){}/* Configure PE0-PE3 as ADC input channel */MAP_GPIOPinTypeADC(GPIO_PORTE_BASE, GPIO_PIN_3);/* Enable the clock to ADC-0 and wait for it to be ready */MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);while(!(MAP_SysCtlPeripheralReady(SYSCTL_PERIPH_ADC0))){}/* Configure Sequencer 2 to sample the analog channel : AIN0-AIN3. The* end of conversion and interrupt generation is set for AIN3 */MAP_ADCSequenceStepConfigure(ADC0_BASE, 2, 0, ADC_CTL_CH1 | ADC_CTL_IE |ADC_CTL_END);/* Enable sample sequence 2 with a timer signal trigger. Sequencer 2* will do a single sample when the timer generates a trigger on timeout*/MAP_ADCSequenceConfigure(ADC0_BASE, 2, ADC_TRIGGER_TIMER, 2);/* Clear the interrupt status flag before enabling. This is done to make* sure the interrupt flag is cleared before we sample. */MAP_ADCIntClearEx(ADC0_BASE, ADC_INT_DMA_SS2);MAP_ADCIntEnableEx(ADC0_BASE, ADC_INT_DMA_SS2);/* Enable the DMA request from ADC0 Sequencer 2 */MAP_ADCSequenceDMAEnable(ADC0_BASE, 2);/* Since sample sequence 2 is now configured, it must be enabled. */MAP_ADCSequenceEnable(ADC0_BASE, 2);/* Enable the Interrupt generation from the ADC-0 Sequencer */MAP_IntEnable(INT_ADC0SS2);/* Enable the DMA and Configure Channel for TIMER0A for Ping Pong mode of* transfer */MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_UDMA);while(!(SysCtlPeripheralReady(SYSCTL_PERIPH_UDMA))){}MAP_uDMAEnable();/* Point at the control table to use for channel control structures. */MAP_uDMAControlBaseSet(pui8ControlTable);/* Map the ADC0 Sequencer 2 DMA channel */MAP_uDMAChannelAssign(UDMA_CH16_ADC0_2);/* Put the attributes in a known state for the uDMA ADC0 Sequencer 2* channel. These should already be disabled by default. */MAP_uDMAChannelAttributeDisable(UDMA_CH16_ADC0_2,UDMA_ATTR_ALTSELECT | UDMA_ATTR_USEBURST |UDMA_ATTR_HIGH_PRIORITY |UDMA_ATTR_REQMASK);/* Configure the control parameters for the primary control structure for* the ADC0 Sequencer 2 channel. The primary control structure is used for* copying the data from ADC0 Sequencer 2 FIFO to srcBuffer. The transfer* data size is 16 bits and the source address is not incremented while* the destination address is incremented at 16-bit boundary.*/MAP_uDMAChannelControlSet(UDMA_CH16_ADC0_2 | UDMA_PRI_SELECT,UDMA_SIZE_16 | UDMA_SRC_INC_NONE | UDMA_DST_INC_16 |UDMA_ARB_4);/* Set up the transfer parameters for the ADC0 Sequencer 2 primary control* structure. The mode is Basic mode so it will run to completion. */MAP_uDMAChannelTransferSet(UDMA_CH16_ADC0_2 | UDMA_PRI_SELECT,UDMA_MODE_BASIC,(void *)&ADC0->SSFIFO2, (void *)&srcBuffer,sizeof(srcBuffer)/2);/* The uDMA ADC0 Sequencer 2 channel is primed to start a transfer. As* soon as the channel is enabled and the Timer will issue an ADC trigger,* the ADC will perform the conversion and send a DMA Request. The data* transfers will begin. */MAP_uDMAChannelEnable(UDMA_CH16_ADC0_2);/* Enable Timer-0 clock and configure the timer in periodic mode with* a frequency of 1 KHz. Enable the ADC trigger generation from the* timer-0. */MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);while(!(MAP_SysCtlPeripheralReady(SYSCTL_PERIPH_TIMER0))){}MAP_TimerConfigure(TIMER0_BASE, TIMER_CFG_A_PERIODIC);MAP_TimerLoadSet(TIMER0_BASE, TIMER_A, (systemClock/1000));MAP_TimerADCEventSet(TIMER0_BASE, TIMER_ADC_TIMEOUT_A);MAP_TimerControlTrigger(TIMER0_BASE, TIMER_A, true);MAP_TimerEnable(TIMER0_BASE, TIMER_A);int a[256];int i=0;/* Wait loop */while(1){/* Wait for the conversion to complete */while(i<256){a[i]=srcBuffer[0];i++;}for(i=0;i<256;i++)UARTprintf("a[%d] = %d\r",i, a[i]);}
}
Yale Li：
您好，请问您是通过什么样的方式来查看srcBuffer的值的？
,
mingzhi Ji：
你好，已经解决了，只要在while(!bgetConvStatus)与bgetConvStatus = false中间加入赋值函数就好了，谢谢
,
Yale Li：
好的，感谢您的分享！
