本帖最后由 我爱你的吻123 于 2015-10-30 14:19 编辑
//###########################################################################
//
// FILE: Example_2823xAdcToDMA.c
//
// TITLE: DSP2823x ADC To DMA
//
// ASSUMPTIONS:
前情提要：所有红色的字体都与这个文件无关，是本人自己添加的解说。
//
// This program requires the DSP2823x header files.
//这个程序需要DSP2823x的头文件配置完全。
// Make sure the CPU clock speed is properly defined in
// DSP2833x_examples.h before compiling this example.
//编译这个例子之前，确定DSP2833x的时钟配置好了。
// Connect the signals to be converted to channel A0, A1, A2, and A3.
//把信号连接到A0, A1, A2, and A3通道。
// As supplied, this project is configured for "boot to SARAM"
// operation. The 2823x Boot Mode table is shown below.
这个工程要配置到从SARAM起动，2823X的起动模式已经在下表显示了。
// For information on configuring the boot mode of an eZdsp,
// please refer to the documentation included with the eZdsp,
//
// $Boot_Table:
//
// GPIO87 GPIO86 GPIO85 GPIO84
// XA15 XA14 XA13 XA12
// PU PU PU PU
// ==========================================
// 1 1 1 1 Jump to Flash
// 1 1 1 0 SCI-A boot
// 1 1 0 1 SPI-A boot
// 1 1 0 0 I2C-A boot
// 1 0 1 1 eCAN-A boot
// 1 0 1 0 McBSP-A boot
// 1 0 0 1 Jump to XINTF x16
// 1 0 0 0 Jump to XINTF x32
// 0 1 1 1 Jump to OTP
// 0 1 1 0 Parallel GPIO I/O boot
// 0 1 0 1 Parallel XINTF boot
// 0 1 0 0 Jump to SARAM <- "boot to SARAM"---------------在这里配置好
// 0 0 1 1 Branch to check boot mode
// 0 0 1 0 Boot to flash, bypass ADC cal
// 0 0 0 1 Boot to SARAM, bypass ADC cal
// 0 0 0 0 Boot to SCI-A, bypass ADC cal
// Boot_Table_End$
//
//
// DESCRIPTION:
//
// ADC is setup to convert 4 channels for each SOC received, with total of 10 SOCs.
// Each SOC initiates 4 conversions.
启动转换 Start of Conversion (SOC)，ADC有四个通道要通过SOC转换。
// DMA is set up to capture the data on each SEQ1_INT. DMA will re-sort
// the data by channel sequentially, i.e. all channel0 data will be together
// all channel1 data will be together.
//DMA被设置为捕捉每个排序器的中断。DMA将按通道排序来重排所有数据。如，所有通道0的数据在一起，通道1的数据在一起。
// Code should stop in local_DINTCH1_ISR when complete
//
// Watch Variables:
// DMABuf1
//
//###########################################################################
//
// Original source by: M.P.
//
// $TI Release: 2833x/2823x Header Files and Peripheral Examples V133 $
// $Release Date: June 8, 2012 $
//###########################################################################
#include "DSP28x_Project.h" // Device Headerfile and Examples Include File
// ADC start parameters ADC开始参数
#if (CPU_FRQ_150MHZ) // Default - 150 MHz SYSCLKOUT 我们缺省用的是系统150MHZ时钟。经过分频为25MHZ.
#define ADC_MODCLK 0x3 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 150/(2*3) = 25.0 MHz
#endif
#if (CPU_FRQ_100MHZ)
#define ADC_MODCLK 0x2 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 100/(2*2) = 25.0 MHz
#endif
#define ADC_CKPS 0x1 // ADC module clock = HSPCLK/2*ADC_CKPS = 25.0MHz/(1*2) = 12.5MHz
#define ADC_SHCLK 0xf // S/H width in ADC module periods = 16 ADC clocks
#define AVG 1000 // Average sample limit 平均样本限制
#define ZOFFSET 0x00 // Average Zero offset 平均零点偏移
#define BUF_SIZE 40 // Sample buffer size 样本缓冲区大小
// Global variable for this example 全局变量
Uint16 j=0;
#pragma DATA_SECTION(DMABuf1,"DMARAML4");
volatile Uint16 DMABuf1[40];
volatile Uint16 *DMADest;
volatile Uint16 *DMASource;
#pragma DATA_SECTION(bufferB, ”my_sect”)
char bufferB[512];
在.cmd文件中建立对应的section就可以使用了。 #pragma DATA_SECTION(函数名或全局变量名,"用户自定义在数据空间的段名"); #pragma CODE_SECTION(函数名或全局变量名,"用户自定义在程序空间的段名"); 注意 不能在函数体内声明。 必须在定义和使用前声明 #pragma可以阻止对未调用的函数的优化
interrupt void local_DINTCH1_ISR(void); 中断
void main(void)
{
Uint16 i;
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2833x_SysCtrl.c file.
InitSysCtrl();时钟设置，在DSP2833x_SysCtrl.c这个文件中有相应的寄存器的值。
// Specific clock setting for this example:
EALLOW;
SysCtrlRegs.HISPCP.all = ADC_MODCLK; // HSPCLK = SYSCLKOUT/ADC_MODCLK HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 100/(2*2) = 25.0 MHz
把ADC打开，用150M/6=25M
EDIS;
// Step 2. Initialize GPIO:
// This example function is found in the DSP2833x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.这个函数InitGpio()是要我们配置好相应的GPIO,就是说你的AD是从哪一个引脚输入的。GPIO有几个寄存器，方向寄存器，通用I/O寄存器等等。
// InitGpio(); // Skipped for this example
// Step 3. Clear all interrupts and initialize PIE vector table:
清除所有的中断，并且初始化PIE,PIE就像是一整套的组合开关，把我们的所有中断都控制了起来，你想要什么样的中断，可以按你的要求来配置。要想知道详情的，可以看我的日志中关于PIECTRL.H 和PIEVECT.H这两篇。我贴了一些图在上面。
// Disable CPU interrupts
DINT;
//---------------------------------------------------------------------------
//关闭CPU中断。这个DINT它是可以理解为一个汇编代码，它在这个DSP2833x_Device.h文件中定义。
Common CPU Definitions:
extern cregister volatile unsigned int IFR;
extern cregister volatile unsigned int IER;
#define EINT asm(" clrc INTM")
#define DINT asm(" setc INTM")
#define ERTM asm(" clrc DBGM")
#define DRTM asm(" setc DBGM")
#define EALLOW asm(" EALLOW")
#define EDIS asm(" EDIS")
#define ESTOP0 asm(" ESTOP0")
// Initialize the PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the DSP2833x_PieCtrl.c file.
InitPieCtrl();------------这外就是PIE的初始化的程序，接下来我会把它打开说说的。也是一种记录的过程。
// Disable CPU interrupts and clear all CPU interrupt flags:
IER = 0x0000;
IFR = 0x0000;--------------------------------extern cregister volatile unsigned int IFR; extern cregister volatile unsigned int IER;这两个地方我有一点搞不明白,它的定义方式有点奇怪，涉及到编译器的自动处理。 cregister
使用cregister关键字，当我们定义的该类型的对象与C28x的标准的控制寄存器匹配时，编译器会自动产生相关的代码去控制对应的寄存器，使得我们可以在高级编程语言C/C++中对寄存器进行控制;如果不匹配则产生编译器错误。目前可匹配此类型的寄存器包括： IER：中断使能寄存器IFR：中断标志寄存器 我们在这里就暂且这么理解一下吧!
// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example. This is useful for debug purposes.
// The shell ISR routines are found in DSP2833x_DefaultIsr.c.
// This function is found in DSP2833x_PieVect.c.
InitPieVectTable();
// Interrupts that are used in this example are re-mapped to
// ISR functions found within this file.
EALLOW; // Allow access to EALLOW protected registers
PieVectTable.DINTCH1= &local_DINTCH1_ISR;
EDIS; // Disable access to EALLOW protected registers
IER = M_INT7 ; //Enable INT7 (7.1 DMA Ch1)
EnableInterrupts();
// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2833x_InitPeripherals.c
// InitPeripherals(); // Not required for this example 串行外设初始化
InitAdc(); // For this example, init the ADC ADC寄存器初始化
// Specific ADC setup for this example:
AdcRegs.ADCTRL1.bit.ACQ_PS = ADC_SHCLK;
AdcRegs.ADCTRL3.bit.ADCCLKPS = ADC_CKPS;
AdcRegs.ADCTRL1.bit.SEQ_CASC = 0; // 0 Non-Cascaded Mode
AdcRegs.ADCTRL2.bit.INT_ENA_SEQ1 = 0x1;
AdcRegs.ADCTRL2.bit.RST_SEQ1 = 0x1;
AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x0;
AdcRegs.ADCCHSELSEQ1.bit.CONV01 = 0x1;
AdcRegs.ADCCHSELSEQ1.bit.CONV02 = 0x2;
AdcRegs.ADCCHSELSEQ1.bit.CONV03 = 0x3;
AdcRegs.ADCCHSELSEQ2.bit.CONV04 = 0x0;
AdcRegs.ADCCHSELSEQ2.bit.CONV05 = 0x1;
AdcRegs.ADCCHSELSEQ2.bit.CONV06 = 0x2;
AdcRegs.ADCCHSELSEQ2.bit.CONV07 = 0x3;
AdcRegs.ADCMAXCONV.bit.MAX_CONV1 = 3; // Set up ADC to perform 4 conversions for every SOC
//Step 5. User specific code, enable interrupts:
// Initialize DMA
DMAInitialize();
// Clear Table
for (i=0; i<BUF_SIZE; i++)
{
DMABuf1 = 0;
}
// Configure DMA Channel
DMADest = &DMABuf1[0]; //Point DMA destination to the beginning of the array
DMASource = &AdcMirror.ADCRESULT0; //Point DMA source to ADC result register base
DMACH1AddrConfig(DMADest,DMASource);
DMACH1BurstConfig(3,1,10);
DMACH1TransferConfig(9,1,0);
DMACH1WrapConfig(1,0,0,1);
DMACH1ModeConfig(DMA_SEQ1INT,PERINT_ENABLE,ONESHOT_DISABLE,CONT_DISABLE,SYNC_DISABLE,SYNC_SRC,
OVRFLOW_DISABLE,SIXTEEN_BIT,CHINT_END,CHINT_ENABLE);
StartDMACH1();
// Start SEQ1
AdcRegs.ADCTRL2.bit.SOC_SEQ1 = 0x1;
for(i=0;i<10;i++){
for(j=0;j<1000;j++){}
AdcRegs.ADCTRL2.bit.SOC_SEQ1 = 1; //Normally ADC will be tied to ePWM, or timed routine
} //For this example will re-start manually
}
// INT7.1
interrupt void local_DINTCH1_ISR(void) // DMA Channel 1
{
// To receive more interrupts from this PIE group, acknowledge this interrupt
PieCtrlRegs.PIEACK.all = PIEACK_GROUP7;
// Next two lines for debug only to halt the processor here
// Remove after inserting ISR Code
asm (" ESTOP0");
for(;;);
}
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