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器件型号：MSP430F5529 大家好、我正在尝试执行一个简单的程序、该程序将 ADC 配置为读取温度、并使用 DMA 将结果发送到 UART 进行传输。 看起来我的 ADC 没有触发我的 DMA、因此当我查看寄存器 UCATXBUF 时、它始终为0x00。
我知道我还没有代码的 UART 比例。 我让该部分处理另一个项目。 因此、在这里、我重点关注通过 DMA 将 ADC 读出到 UCATXBUF。
#include <msp430.h>
#include <stdint.h>
#define ADC_RESULTION_BITS 12
void DMA_config (void)
// configure DMA0
{
// Setup DMA0
DMACTL0 = DMA0TSEL_24; // ADC12IFGx triggered
DMACTL4 = DMARMWDIS; // Read-modify-write disable
DMA0CTL &= ~DMAIFG;
DMA0CTL = DMADT_4+DMAEN+DMADSTINCR_0+DMASRCINCR_0+DMAIE; // Rpt single tranfer, unchanged src & dst, Int
DMA0SZ = 1; // Block size
__data20_write_long((uintptr_t) &DMA0SA,(uintptr_t) &ADC12MEM0); // Source block address
__data20_write_long((uintptr_t) &DMA0DA,(uintptr_t) &UCA1TXBUF); // Destination single address
}
void ADC_config()
{
// ADC Core control
ADC12CTL0 |= 0x00; // Initialize ADC12CTL0 register (Turn ADC12 OFF before configure it)
ADC12CTL0 |= ADC12SHT00 + ADC12SHT01 + ADC12SHT02 + ADC12SHT03;
ADC12CTL0 |= ADC12SHT10 + ADC12SHT11 + ADC12SHT12 + ADC12SHT13; // Sample-and-hold time set to 1024 ADC12CLK cycle
REFCTL0 |= (REFMSTR + REFON + REFVSEL_3); // Reference voltage 2.5V
ADC12CTL1 |= 0x00; // Initialize ADC12CTL1 register
ADC12CTL1 |= ADC12SHP; // S/H signal comes from Sample Timer
ADC12CTL1 |= ADC12SSEL0; // Set ADC12 clock source to ACLK (32,768kHz)
ADC12CTL1 |= ADC12DIV0 + ADC12DIV1 + ADC12DIV2; // Set ADC12 divider to 8
ADC12MCTL0 |= 0x0A; // Configure 12-bit ADC0 control register to 0x0A (1010b) for temperature diode
ADC12MCTL0 |= ADC12SREF0; // Select reference voltage (VREF+ and VR- = AVSS)
ADC12CTL2 |= 0x00; // Initialize ADC12CTL2 register
ADC12CTL2 |= ADC12PDIV; // Set ADC12 pre-divider to 4
ADC12CTL2 |= ADC12RES_2; // 12-bit resolution
ADC12IE |= ADC12IE0; // Enable ADC12 Interrupt on Memory 0
ADC12IFG |= ADC12IFG0;
ADC12CTL0 |= ADC12ON; // ADC12 Turn ON
ADC12CTL0 |= ADC12ENC | ADC12SC; // Enable ADC
}
int main(void)
{
ADC_config();
DMA_config();
__bis_SR_register(LPM0_bits + GIE); // LPM0 w/ interrupts
__no_operation(); // used for debugging
}
//------------------------------------------------------------------------------
// DMA Interrupt Service Routine
//------------------------------------------------------------------------------
#pragma vector=DMA_VECTOR
__interrupt void DMA_ISR(void)
{
switch(__even_in_range(DMAIV,16))
{
case 0: break;
case 2: // DMA0IFG = DMA Channel 0
P1OUT ^= BIT0; // Toggle P1.0 - PLACE BREAKPOINT HERE AND CHECK DMA_DST VARIABLE
break;
case 4: break; // DMA1IFG = DMA Channel 1
case 6: break; // DMA2IFG = DMA Channel 2
case 8: break; // DMA3IFG = DMA Channel 3
case 10: break; // DMA4IFG = DMA Channel 4
case 12: break; // DMA5IFG = DMA Channel 5
case 14: break; // DMA6IFG = DMA Channel 6
case 16: break; // DMA7IFG = DMA Channel 7
default: break;
}
}
ADC 中断标志已置1：
但 DMA 没有将数据传输到 TxBuffer：
我完全知道从12位 ADC 读取的数据是1字宽(16位)、而目的寄存器 UCATXBUF 只有8位。 根据 MSP430用户指南"当字到字节传输时、只传输源字的低字节。" 因此在本示例中、我希望将0xED 写入 UCATXBUF、但它报告的是0x00
