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本帖最后由 一只耳朵怪 于 2018-6-13 16:05 编辑
如果主程序执行是的一个状态机,时序要求比较严格,那么是不是搬移到RAM中执行的会快一点,那么怎么把main的主要代码都搬移到RAM中里面呢? 就是for(;;)之后的代码? |
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在应用中为了提高关键代码的执行速度,可以通过将Flash中的对应代码搬移到RAM中执行。具体的实现一般分为4步:
(1)在cmd文件中声明ramfuncs地址空间,包括代码在Load(下载)和Run(执行)时所分别对应的Flash和RAM地址; (2)定义代码搬移函数,MemCopy():其主要功能为将Flash所对应的代码搬移至RAM; (3)在main.c中首先声明需要搬移的函数,声明三个外部变量,执行MemCopy(),将对应的函数搬移至RAM中; (4)在工程中添加以上的操作,便可以正常调用相关函数,该函数会自动跳转至RAM中运行。 补充: 为了有效地提升代码执行速率,建议只将部分关键代码搬移至RAM中运行,没有必要将main()主函数的全部代码搬移至RAM。 |
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freedom0zh 发表于 2018-6-13 07:53 您好,请问为什么跑马灯程序在带仿真器时运行比不带仿真器下运行快呢?跑马灯所用的延时程序已经搬移到ram了。 |
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如果程序中的跑马灯是通过定时器中断来实现的话,那么程序运行的快慢还应该与相应的中断响应函数在 RAM 中还是 Flash 中运行有关。 |
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我已经把灯的亮灭在定时中断程序,中断程序放在RAM中运行,可是还是会出当拿掉仿真器后速度会变慢很多,附件中是我的代码,麻烦帮忙看一看 #include "DSP280x_Device.h" // DSP280x Headerfile Include File #include "DSP280x_Examples.h" // DSP280x Examples Include File // Configure which ePWM timer interrupts are enabled at the PIE level: // 1 = enabled, 0 = disabled #define PWM3_INT_ENABLE 1 // Configure the period for each timer #define PWM3_TIMER_TBPRD 0x1FFF // Make this long enough so that we can see an LED toggle #define DELAY 1000000L #define DELAY1 100000L // Functions that will be run from RAM need to be assigned to // a different section. This section will then be mapped using // the linker cmd file. #pragma CODE_SECTION(epwm3_timer_isr, "ramfuncs"); // Prototype statements for functions found within this file. interrupt void epwm3_timer_isr(void); void InitEPwmTimer(void); void Gpio_select(void); // Global variables used in this example Uint32 EPwm1TimerIntCount; Uint32 EPwm2TimerIntCount; Uint32 EPwm3TimerIntCount; Uint32 LoopCount; // These are defined by the linker (see F2808.cmd) extern Uint16 RamfuncsLoadStart; extern Uint16 RamfuncsLoadEnd; extern Uint16 RamfuncsRunStart; void main(void) [ // Step 1. Initialize System Control: // PLL, WatchDog, enable Peripheral Clocks // This example function is found in the DSP280x_SysCtrl.c file. InitSysCtrl(); // Step 2. Initalize GPIO: // This example function is found in the DSP280x_Gpio.c file and // illustrates how to set the GPIO to it's default state. // InitGpio(); // Skipped for this example EALLOW; GpioCtrlRegs.GPAMUX1.all = 0x0; // GPIO pin GpioCtrlRegs.GPADIR.all = 0xFF; // Output pin GpioDataRegs.GPADAT.all =0xFF; // Close LEDs EDIS; // For this example use the following configuration: Gpio_select(); // Step 3. Clear all interrupts and initialize PIE vector table: // Disable CPU interrupts DINT; // 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 DSP280x_PieCtrl.c file. InitPieCtrl(); // Disable CPU interrupts and clear all CPU interrupt flags: IER = 0x0000; IFR = 0x0000; // 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 DSP280x_DefaultIsr.c. // This function is found in DSP280x_PieVect.c. InitPieVectTable(); // Interrupts that are used in this example are re-mapped to // ISR functions found within this file. EALLOW; // This is needed to write to EALLOW protected registers // PieVectTable.EPWM1_INT = &epwm1_timer_isr; // PieVectTable.EPWM2_INT = &epwm2_timer_isr; PieVectTable.EPWM3_INT = &epwm3_timer_isr; EDIS; // This is needed to disable write to EALLOW protected registers // Step 4. Initialize all the Device Peripherals: // This function is found in DSP280x_InitPeripherals.c // InitPeripherals(); // Not required for this example InitEPwmTimer(); // For this example, only initialize the ePWM Timers MemCopy(&RamfuncsLoadStart, &RamfuncsLoadEnd, &RamfuncsRunStart); // Call Flash Initialization to setup flash waitstates // This function must reside in RAM InitFlash(); // Initalize counters: EPwm1TimerIntCount = 0; EPwm2TimerIntCount = 0; EPwm3TimerIntCount = 0; LoopCount = 0; // Enable CPU INT3 which is connected to EPWM1-3 INT: IER |= M_INT3; // Enable EPWM INTn in the PIE: Group 3 interrupt 1-3 PieCtrlRegs.PIEIER3.bit.INTx3 = PWM3_INT_ENABLE; // Enable global Interrupts and higher priority real-time debug events: EINT; // Enable Global interrupt INTM ERTM; // Enable Global realtime interrupt DBGM // Step 6. IDLE loop. Just sit and loop forever (optional): EALLOW; GpioCtrlRegs.GPBMUX1.bit.GPIO34 = 0; GpioCtrlRegs.GPBDIR.bit.GPIO34 = 1; EDIS; for(;;) [ // This loop will be interrupted, so the overall // delay between pin toggles will be longer. DELAY_US(DELAY); LoopCount++; GpioDataRegs.GPBTOGGLE.bit.GPIO34 = 1; ] ] void InitEPwmTimer() [ EALLOW; SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0; // Stop all the TB clocks EDIS; // Setup Sync EPwm3Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; // Pass through // Allow each timer to be sync'ed EPwm3Regs.TBCTL.bit.PHSEN = TB_ENABLE; EPwm3Regs.TBPHS.half.TBPHS = 300; EPwm3Regs.TBPRD = PWM3_TIMER_TBPRD; EPwm3Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Count up EPwm3Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; // Enable INT on Zero event EPwm3Regs.ETSEL.bit.INTEN = PWM3_INT_ENABLE; // Enable INT EPwm3Regs.ETPS.bit.INTPRD = ET_3RD; // Generate INT on 3rd event EALLOW; SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1; // Start all the timers synced EDIS; ] interrupt void epwm3_timer_isr(void) [ Uint16 i; EPwm3TimerIntCount++; // Short Delay to simulate some ISR Code for(i = 1; i < 0x01FF; i++) [] GpioDataRegs.GPADAT.all=0xFFFDFFFF; //GPIO17=0 LED灯亮 DELAY_US(DELAY1); GpioDataRegs.GPADAT.all=0xFFF7FFFF; //GPIO19=0 DELAY_US(DELAY1); // Clear INT flag for this timer EPwm3Regs.ETCLR.bit.INT = 1; // Acknowledge this interrupt to receive more interrupts from group 3 PieCtrlRegs.PIEACK.all = PIEACK_GROUP3; ] void Gpio_select(void) [ EALLOW; GpioCtrlRegs.GPAPUD.bit.GPIO6 = 0; // Enable pullup on GPIO11 GpioDataRegs.GPASET.bit.GPIO6 = 1; // Load output latch GpioCtrlRegs.GPAMUX1.bit.GPIO6 = 0; // GPIO11 = GPIO GpioCtrlRegs.GPADIR.bit.GPIO6 = 1; // GPIO11 = output GpioCtrlRegs.GPAPUD.bit.GPIO16= 0; // Enable pullup on GPIO11 GpioDataRegs.GPASET.bit.GPIO16 = 1; // Load output latch GpioCtrlRegs.GPAMUX2.bit.GPIO16 = 0; // GPIO11 = GPIO GpioCtrlRegs.GPADIR.bit.GPIO16 = 1; // GPIO11 = output GpioCtrlRegs.GPAPUD.bit.GPIO17 = 0; // Enable pullup on GPIO11 GpioDataRegs.GPASET.bit.GPIO17 = 1; // Load output latch GpioCtrlRegs.GPAMUX2.bit.GPIO17 = 0; // GPIO11 = GPIO GpioCtrlRegs.GPADIR.bit.GPIO17 = 1; // GPIO11 = output GpioCtrlRegs.GPAPUD.bit.GPIO19 = 0; // Enable pullup on GPIO11 GpioDataRegs.GPASET.bit.GPIO19 = 1; // Load output latch GpioCtrlRegs.GPAMUX2.bit.GPIO19 = 0; // GPIO11 = GPIO GpioCtrlRegs.GPADIR.bit.GPIO19= 1; // GPIO11 = output GpioCtrlRegs.GPAPUD.bit.GPIO8 = 0; // Enable pullup on GPIO11 GpioDataRegs.GPASET.bit.GPIO8 = 1; // Load output latch GpioCtrlRegs.GPAMUX1.bit.GPIO8 = 0; // GPIO11 = GPIO GpioCtrlRegs.GPADIR.bit.GPIO8 = 1; // GPIO11 = output GpioCtrlRegs.GPAMUX2.bit.GPIO31 = 0; // GPIO11 = GPIO GpioCtrlRegs.GPADIR.bit.GPIO31 = 0; // GPIO11 = output EDIS; ] |
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