[第一讲]DSP28335将Flash中的代码拷贝到RAM中运行

背景：

近期需要使用28335完成一个简单的逆变器设计，由于开关频率为81kHz，每个开关周期只有12.34us，担心在每个开关期间无法完成相应的计算工作，因此想到了将代码烧写时放在Flash中，初始化时拷贝到RAM中运行的办法，经实测，代码运行速度提升20%~250%不等.

那就开始吧，关于28335的工程模板部分，过于简单，相关的文章也够多，在此省略。

方式一（适用于较大的工程）：将部分函数拷贝到RAM中运行

众所周知，28335拥有512KB的Flash与68KB的RAM，庞大的工程往往无法实现所有代码都放在RAM中运行，因此，将部分对运算速度非常敏感的函数放在RAM中运行，往往是常用的方法。

首先需要在CMD文件中划分空间，划分出用来存放函数的Flash区域和运行函数的RAM区域，见下列 /* User Define areas below: */之后的部分。

实际上该段落写在SECTIONS的任意位置都可以。

SECTIONS
{/* Allocate program areas: */.cinit              : > FLASHA      PAGE = 0.pinit              : > FLASHA,     PAGE = 0.text               : > FLASHA      PAGE = 0codestart           : > BEGIN       PAGE = 0
#ifdef __TI_COMPILER_VERSION__#if __TI_COMPILER_VERSION__ >= 15009000.TI.ramfunc : {} LOAD = FLASHG,RUN = RAML2,LOAD_START(_RamfuncsLoadStart),LOAD_END(_RamfuncsLoadEnd),RUN_START(_RamfuncsRunStart),LOAD_SIZE(_RamfuncsLoadSize),PAGE = 0#elseramfuncs       : LOAD = FLASHG,RUN = RAML2,LOAD_START(_RamfuncsLoadStart),LOAD_END(_RamfuncsLoadEnd),RUN_START(_RamfuncsRunStart),LOAD_SIZE(_RamfuncsLoadSize),PAGE = 0#endif
#endif/* User Define areas below: */Myspace            : LOAD = FLASHH,RUN = RAML3,LOAD_START(_MyspaceLoadStart),LOAD_END(_MyspaceLoadEnd),RUN_START(_MyspaceRunStart),LOAD_SIZE(_MyspaceLoadSize),PAGE = 0/* User Define areas above: */csmpasswds          : > CSM_PWL     PAGE = 0csm_rsvd            : > CSM_RSVD    PAGE = 0

从图中可以看出，划分的区域叫作Myspace，存储的区域为FLASHH,初始化后运行的区域为RAML3。

其中的_MyspaceLoadStart等地址划分不用管，CCS会自动生成相应的地址区域，名称可以任意，注意格式即可。

下面来看看CMD文件的前段内容：

MEMORY
{
PAGE 0:    /* Program Memory *//* Memory (RAM/FLASH/OTP) blocks can be moved to PAGE1 for data allocation */ZONE0       : origin = 0x004000, length = 0x001000     /* XINTF zone 0 */RAML0       : origin = 0x008000, length = 0x001000     /* on-chip RAM block L0 */RAML1       : origin = 0x009000, length = 0x001000     /* on-chip RAM block L1 */RAML2       : origin = 0x00A000, length = 0x001000     /* on-chip RAM block L2 */RAML3       : origin = 0x00B000, length = 0x001000     /* on-chip RAM block L3 */ZONE6       : origin = 0x0100000, length = 0x100000    /* XINTF zone 6 */ ZONE7A      : origin = 0x0200000, length = 0x00FC00    /* XINTF zone 7 - program space */ FLASHH      : origin = 0x300000, length = 0x008000     /* on-chip FLASH */FLASHG      : origin = 0x308000, length = 0x008000     /* on-chip FLASH */FLASHF      : origin = 0x310000, length = 0x008000     /* on-chip FLASH */FLASHE      : origin = 0x318000, length = 0x008000     /* on-chip FLASH */FLASHD      : origin = 0x320000, length = 0x008000     /* on-chip FLASH */FLASHC      : origin = 0x328000, length = 0x008000     /* on-chip FLASH */FLASHA      : origin = 0x338000, length = 0x007F80     /* on-chip FLASH */CSM_RSVD    : origin = 0x33FF80, length = 0x000076     /* Part of FLASHA.  Program with all 0x0000 when CSM is in use. */BEGIN       : origin = 0x33FFF6, length = 0x000002     /* Part of FLASHA.  Used for "boot to Flash" bootloader mode. */CSM_PWL     : origin = 0x33FFF8, length = 0x000008     /* Part of FLASHA.  CSM password locations in FLASHA */OTP         : origin = 0x380400, length = 0x000400     /* on-chip OTP */ADC_CAL     : origin = 0x380080, length = 0x000009     /* ADC_cal function in Reserved memory */IQTABLES    : origin = 0x3FE000, length = 0x000b50     /* IQ Math Tables in Boot ROM */IQTABLES2   : origin = 0x3FEB50, length = 0x00008c     /* IQ Math Tables in Boot ROM */  FPUTABLES   : origin = 0x3FEBDC, length = 0x0006A0     /* FPU Tables in Boot ROM */ROM         : origin = 0x3FF27C, length = 0x000D44     /* Boot ROM */        RESET       : origin = 0x3FFFC0, length = 0x000002     /* part of boot ROM  */VECTORS     : origin = 0x3FFFC2, length = 0x00003E     /* part of boot ROM  */PAGE 1 :   /* Data Memory *//* Memory (RAM/FLASH/OTP) blocks can be moved to PAGE0 for program allocation *//* Registers remain on PAGE1                                                  */BOOT_RSVD   : origin = 0x000000, length = 0x000050     /* Part of M0, BOOT rom will use this for stack */RAMM0       : origin = 0x000050, length = 0x0003B0     /* on-chip RAM block M0 */RAMM1       : origin = 0x000400, length = 0x000400     /* on-chip RAM block M1 */RAML4       : origin = 0x00C000, length = 0x001000     /* on-chip RAM block L1 */RAML5       : origin = 0x00D000, length = 0x001000     /* on-chip RAM block L1 */RAML6       : origin = 0x00E000, length = 0x001000     /* on-chip RAM block L1 */RAML7       : origin = 0x00F000, length = 0x001000     /* on-chip RAM block L1 */ZONE7B      : origin = 0x20FC00, length = 0x000400     /* XINTF zone 7 - data space */FLASHB      : origin = 0x330000, length = 0x008000     /* on-chip FLASH */
}

图中PAGE0划分了存储程序的区域，PAGE1划分了存储数据的区域，因为28335是哈佛结构，因此数据和程序的总线地址并不会重叠，例如FLASHB是数据存储区域，但其地址处于FLASHA与FLASHC之间。

划分好了地址，下一步需要对定义的函数进行搬运，在主程序中添加以下代码：

extern Uint16 MyspaceLoadStart;
extern Uint16 MyspaceLoadEnd;
extern Uint16 MyspaceRunStart;//define user Functions
void beep();
#pragma CODE_SECTION(beep,"Myspace")

声明了CMD文件中拥有的地址，并为定义的函数beep()划分了相应的存储运行空间，也就是上面定义的Myspace。

随后，在主函数中加入MemCopy()与InitFlash()函数，后者确保了函数烧写在了Flash中，并且Flash可以正常工作。前者则是将Flash中的介于MyspaceLoadStart, MyspaceLoadEnd之间的代码搬运到RAM中进行初始化。

void main()
{InitSysCtrl();MemCopy(&MyspaceLoadStart, &MyspaceLoadEnd, &MyspaceRunStart);InitFlash();Gpio_init();while(1){//SRAM中程序运行速度是flash中的两倍beep();}
}

随后对beep()函数进行定义，为了尽可能公平公正的展示代码的运行速度，函数中包含了浮点加减乘除运算与三角运算，同时还有一些对寄存器的操作语句，随后与Flash中运行的代码进行对比，检验代码运行速度的变化。

void beep()
{float a;                              float b=2.843;a=sin(b);a=b*3.14;a=b+3.25;a=b/0.98;b=a*b;GpioDataRegs.GPCSET.bit.GPIO64=1;GpioDataRegs.GPCCLEAR.bit.GPIO64=1;GpioDataRegs.GPCDAT.bit.GPIO64=1;GpioDataRegs.GPCTOGGLE.bit.GPIO64=1;
}

下面开始速度测试部分：

将代码运行使用的时钟周期（1/150M）写在代码后，可以看到此时的速度如下,总用时484时钟周期，RAM运行总时间约为3.2us。

void beep()
{float a;            //1float b=2.843;      //2a=sin(b);           //151a=b*3.14;           //6a=b+3.25;           //4a=b/0.98;           //259b=a*b;              //4GpioDataRegs.GPCSET.bit.GPIO64=1;      //4GpioDataRegs.GPCCLEAR.bit.GPIO64=1;    //1GpioDataRegs.GPCDAT.bit.GPIO64=1;      //1GpioDataRegs.GPCTOGGLE.bit.GPIO64=1;   //4GpioDataRegs.GPCTOGGLE.bit.GPIO64=1;   //1
}

再看FLASH中的运行速度：

void beep()
{float a;            //6float b=2.843;      //6a=sin(b);           //185a=b*3.14;           //19a=b+3.25;           //13a=b/0.98;           //361b=a*b;              //13GpioDataRegs.GPCSET.bit.GPIO64=1;    //7GpioDataRegs.GPCCLEAR.bit.GPIO64=1;  //1GpioDataRegs.GPCDAT.bit.GPIO64=1;    //6GpioDataRegs.GPCTOGGLE.bit.GPIO64=1; //1
}

FLASH中运行总时间约为3.7us。

使用内部FLASH缺点是访问FLASH需要等待状态，这使得程序的运行变慢。在大多数应用中，这不是一个问题。其他一些应用中可能会为了获得最高的运行速度要求无等待状态。内部RAM存储器具有零等待状态，它是易失性存储器。所以，引导的初始化代码段不可以存储在此存储器中。

实际上，虽然将代码写进了RAM中，但代码中的数据与代码内调用的函数可能还在FLASH中存储，无法做到全局的零等待状态，因此，在代码量较小的情况下，可以将全部代码拷贝到RAM中运行，也即引出了方式二。

方式二（适用于较小的工程）：将所有程序拷贝到RAM中运行

这种方式需要编写汇编程序来完成代码从Flash到RAM的复制。该汇编代码在复位向量后调用c_int00之前执行。这保证了在c_int00调用mian()之前完成复制。

编译器生成的包含代码和数据的多个部分，称为段。

下表列出了各种汇编段代表的含义，包括初始化了的和没被初始化的段，初始化的部分是由所有的代码，常量和初始化表组成的。

初始化段
段名	内容	限制
.cinit	显式初始化的全局变量和静态变量表	代码
.const	显式初始化的全局和静态的const变量和字符串常量	不超过64K长度
.econst	长调用的常量	数据中的任何地方
.pinit	全局对象的构造函数表	代码
.switch	switch语句产生的表	代码或者数据
.text	可执行代码和常数	代码

没初始化的段是由未初始化的变量，堆栈和malloc产生的内存。下表列出了由编译器产生的没初始化段。

没初始化段
段名	内容	限制
.bss	全局和静态变量	不超过64K长度
.ebss	长调用的全局或静态变量	数据中的任何地方
.stack	堆栈空间	不超过64K长度
.sysmem	malloc函数产生的内存	不超过64K长度
.esysmem	far_malloc函数产生的内存	数据中的任何地方

当编译器生成的这些段，连接器会从各个源文件中取出这些段，并结合它们来创建一个输出文件。连接器命令文件（.cmd）就是用来告诉连接器去哪里找这些段的。初始化段必须分配到非易失性存储器，如flash/ ROM，当电源被撤除时，程序不会消失。未初始化的段可以被分配到RAM中，因为它们是在代码执行期间被初始化的。

而用户写好程序后，各种变量与函数已经被安排到了各种段名下，此时只需要将相应的段名安排到FLASH中，并在初始化时全部拷贝到RAM中即可。

为了实现以上功能，需要重写以下文件，大家直接复制代码粘贴在相应文件中即可：

Source目录下的：

DSP2833x_usDelay.asm

       .def _DSP28x_usDelay.text.global  __DSP28x_usDelay
_DSP28x_usDelay:SUB    ACC,#1BF     _DSP28x_usDelay,GEQ    ;; Loop if ACC >= 0LRETR

DSP28xxx_CodeStartBranch.asm

WD_DISABLE   .set    1       ;set to 1 to disable WD, else set to 0.ref copy_sections.global code_start***********************************************************************
* Function: codestart section
*
* Description: Branch to code starting point
***********************************************************************.sect "codestart"code_start:.if WD_DISABLE == 1LB wd_disable       ;Branch to watchdog disable code.elseLB copy_sections    ;Branch to copy_sections .endif;end codestart section***********************************************************************
* Function: wd_disable
*
* Description: Disables the watchdog timer
***********************************************************************.if WD_DISABLE == 1.sect "wddisable"
wd_disable:SETC OBJMODE        ;Set OBJMODE for 28x object codeEALLOW              ;Enable EALLOW protected register accessMOVZ DP, #7029h>>6  ;Set data page for WDCR registerMOV @7029h, #0068h  ;Set WDDIS bit in WDCR to disable WDEDIS                ;Disable EALLOW protected register accessLB copy_sections    ;Branch to copy_sections .endif;end wd_disable.end

CMD目录下的：

DSP2833x_nonBIOS_flash.cmd（也可能叫dsp28335.cmd）

MEMORY
{
PAGE 0:    /* Program Memory *//* Memory (RAM/FLASH/OTP) blocks can be moved to PAGE1 for data allocation */ZONE0       : origin = 0x004000, length = 0x001000     /* XINTF zone 0 */RAM_L0L1L2L3: origin = 0x008000, length = 0x004000    /* on-chip RAM */OTP         : origin = 0x380400, length = 0x000400     /* on-chip OTP */ZONE6       : origin = 0x100000, length = 0x100000     /* XINTF zone 6 */ ZONE7A      : origin = 0x200000, length = 0x00FC00     /* XINTF zone 7 - program space */FLASHH      : origin = 0x300000, length = 0x008000     /* on-chip FLASH */FLASHG      : origin = 0x308000, length = 0x008000     /* on-chip FLASH */FLASHF      : origin = 0x310000, length = 0x008000     /* on-chip FLASH */FLASHE      : origin = 0x318000, length = 0x008000     /* on-chip FLASH */FLASHD      : origin = 0x320000, length = 0x008000     /* on-chip FLASH */FLASHC      : origin = 0x328000, length = 0x008000     /* on-chip FLASH */FLASHA      : origin = 0x338000, length = 0x007F80     /* on-chip FLASH */CSM_RSVD    : origin = 0x33FF80, length = 0x000076     /* Part of FLASHA.  Program with all 0x0000 when CSM is in use. */BEGIN_FLASH : origin = 0x33FFF6, length = 0x000002     /* Part of FLASHA.  Used for "boot to Flash" bootloader mode. */CSM_PWL     : origin = 0x33FFF8, length = 0x000008     /* Part of FLASHA.  CSM password locations in FLASHA */ADC_CAL     : origin = 0x380080, length = 0x000009    /* Part of TI OTP */IQTABLES    : origin = 0x3FE000, length = 0x000b50     /* IQ Math Tables in Boot ROM */IQTABLES2   : origin = 0x3FEB50, length = 0x00008c     /* IQ Math Tables in Boot ROM */  FPUTABLES   : origin = 0x3FEBDC, length = 0x0006A0     /* FPU Tables in Boot ROM */ROM         : origin = 0x3FF27C, length = 0x000D44     /* Boot ROM */RESET       : origin = 0x3FFFC0, length = 0x000002     /* part of boot ROM  */VECTORS     : origin = 0x3FFFC2, length = 0x00003E     /* part of boot ROM  */PAGE 1 :   /* Data Memory *//* Memory (RAM/FLASH/OTP) blocks can be moved to PAGE0 for program allocation *//* Registers remain on PAGE1                                                  */RAMM0       : origin = 0x000000, length = 0x000400     /* on-chip RAM block M0 */BOOT_RSVD   : origin = 0x000400, length = 0x000080     /* Part of M1, BOOT rom will use this for stack */RAMM1       : origin = 0x000480, length = 0x000380     /* on-chip RAM block M1 */RAML4       : origin = 0x00C000, length = 0x001000     /* on-chip RAM block L4 */RAML5       : origin = 0x00D000, length = 0x001000     /* on-chip RAM block L5 */RAML6       : origin = 0x00E000, length = 0x001000     /* on-chip RAM block L6 */RAML7       : origin = 0x00F000, length = 0x001000     /* on-chip RAM block L7 */ZONE7B      : origin = 0x20FC00, length = 0x000400     /* XINTF zone 7 - data space */
}/**************************************************************/
/* Link all user defined sections                             */
/**************************************************************/
SECTIONS
{/*** Code Security Password Locations ***/csmpasswds      : > CSM_PWL       PAGE = 0csm_rsvd        : > CSM_RSVD        PAGE = 0/*** User Defined Sections ***/codestart       : > BEGIN_FLASH, PAGE = 0        /* Used by file CodeStartBranch.asm */wddisable        : > FLASHA,          PAGE = 0   copysections    : > FLASHA,          PAGE = 0/* Allocate IQ math areas: */IQmath           : > FLASHC            PAGE = 0        /* Math Code */IQmathTables     : > IQTABLES,       PAGE = 0, TYPE = NOLOAD IQmathTables2    : > IQTABLES2,        PAGE = 0, TYPE = NOLOAD FPUmathTables    : > FPUTABLES,        PAGE = 0, TYPE = NOLOAD /* Allocate DMA-accessible RAM sections: */DMARAML4         : > RAML4,             PAGE = 1DMARAML5         : > RAML5,             PAGE = 1DMARAML6         : > RAML6,             PAGE = 1DMARAML7         : > RAML7,             PAGE = 1/* Allocate 0x400 of XINTF Zone 7 to storing data */ZONE7DATA        : > ZONE7B,            PAGE = 1/* Allocate ADC_cal function (pre-programmed by factory into TI reserved memory) */.adc_cal        : load = ADC_CAL,   PAGE = 0, TYPE = NOLOAD /* .reset is a standard section used by the compiler.  It contains the */
/* the address of the start of _c_int00 for C Code.   /*
/* When using the boot ROM this section and the CPU vector */
/* table is not needed.  Thus the default type is set here to  */
/* DSECT  */ .reset             : > RESET,       PAGE = 0, TYPE = DSECTvectors         : > VECTORS      PAGE = 0, TYPE = DSECT/*** Uninitialized Sections ***/.stack          : > RAMM0        PAGE = 1.ebss           : > RAMM1           PAGE = 1.esysmem        : > RAMM1           PAGE = 1/*** Initialized Sections ***/                                          .cinit         :   LOAD = FLASHA,     PAGE = 0        /* can be ROM */ RUN = RAM_L0L1L2L3, PAGE = 0        /* must be CSM secured RAM */LOAD_START(_cinit_loadstart),RUN_START(_cinit_runstart),SIZE(_cinit_size).const            :   LOAD = FLASHA,     PAGE = 0        /* can be ROM */ RUN = RAM_L0L1L2L3,  PAGE = 0        /* must be CSM secured RAM */LOAD_START(_const_loadstart),RUN_START(_const_runstart),SIZE(_const_size).econst          :   LOAD = FLASHA,     PAGE = 0        /* can be ROM */ RUN = RAM_L0L1L2L3, PAGE = 0        /* must be CSM secured RAM */LOAD_START(_econst_loadstart),RUN_START(_econst_runstart),SIZE(_econst_size).pinit         :   LOAD = FLASHA,     PAGE = 0        /* can be ROM */ RUN = RAM_L0L1L2L3, PAGE = 0        /* must be CSM secured RAM */LOAD_START(_pinit_loadstart),RUN_START(_pinit_runstart),SIZE(_pinit_size).switch           :   LOAD = FLASHA,     PAGE = 0        /* can be ROM */ RUN = RAM_L0L1L2L3, PAGE = 0        /* must be CSM secured RAM */LOAD_START(_switch_loadstart),RUN_START(_switch_runstart),SIZE(_switch_size).text          :   LOAD = FLASHA,         PAGE = 0        /* can be ROM */ RUN = RAM_L0L1L2L3, PAGE = 0        /* must be CSM secured RAM */LOAD_START(_text_loadstart),RUN_START(_text_runstart),SIZE(_text_size)
}

DSP2833x_Headers_nonBIOS.cmd

MEMORY
{PAGE 0:    /* Program Memory */PAGE 1:    /* Data Memory */DEV_EMU     : origin = 0x000880, length = 0x000180     /* device emulation registers */FLASH_REGS  : origin = 0x000A80, length = 0x000060     /* FLASH registers */CSM         : origin = 0x000AE0, length = 0x000010     /* code security module registers */ADC_MIRROR  : origin = 0x000B00, length = 0x000010     /* ADC Results register mirror */XINTF       : origin = 0x000B20, length = 0x000020     /* external interface registers */CPU_TIMER0  : origin = 0x000C00, length = 0x000008     /* CPU Timer0 registers */CPU_TIMER1  : origin = 0x000C08, length = 0x000008     /* CPU Timer0 registers (CPU Timer1 & Timer2 reserved TI use)*/CPU_TIMER2  : origin = 0x000C10, length = 0x000008     /* CPU Timer0 registers (CPU Timer1 & Timer2 reserved TI use)*/PIE_CTRL    : origin = 0x000CE0, length = 0x000020     /* PIE control registers */PIE_VECT    : origin = 0x000D00, length = 0x000100     /* PIE Vector Table */DMA         : origin = 0x001000, length = 0x000200     /* DMA Rev 0 registers */MCBSPA      : origin = 0x005000, length = 0x000040     /* McBSP-A registers */MCBSPB      : origin = 0x005040, length = 0x000040     /* McBSP-B registers */ECANA       : origin = 0x006000, length = 0x000040     /* eCAN-A control and status registers */ ECANA_LAM   : origin = 0x006040, length = 0x000040     /* eCAN-A local acceptance masks */ECANA_MOTS  : origin = 0x006080, length = 0x000040     /* eCAN-A message object time stamps */ECANA_MOTO  : origin = 0x0060C0, length = 0x000040     /* eCAN-A object time-out registers */ECANA_MBOX  : origin = 0x006100, length = 0x000100     /* eCAN-A mailboxes */ECANB       : origin = 0x006200, length = 0x000040     /* eCAN-B control and status registers */ ECANB_LAM   : origin = 0x006240, length = 0x000040     /* eCAN-B local acceptance masks */ECANB_MOTS  : origin = 0x006280, length = 0x000040     /* eCAN-B message object time stamps */ECANB_MOTO  : origin = 0x0062C0, length = 0x000040     /* eCAN-B object time-out registers */ECANB_MBOX  : origin = 0x006300, length = 0x000100     /* eCAN-B mailboxes */EPWM1       : origin = 0x006800, length = 0x000022     /* Enhanced PWM 1 registers */EPWM2       : origin = 0x006840, length = 0x000022     /* Enhanced PWM 2 registers */EPWM3       : origin = 0x006880, length = 0x000022     /* Enhanced PWM 3 registers */EPWM4       : origin = 0x0068C0, length = 0x000022     /* Enhanced PWM 4 registers */EPWM5       : origin = 0x006900, length = 0x000022     /* Enhanced PWM 5 registers */EPWM6       : origin = 0x006940, length = 0x000022     /* Enhanced PWM 6 registers */ECAP1       : origin = 0x006A00, length = 0x000020     /* Enhanced Capture 1 registers */ECAP2       : origin = 0x006A20, length = 0x000020     /* Enhanced Capture 2 registers */ECAP3       : origin = 0x006A40, length = 0x000020     /* Enhanced Capture 3 registers */ECAP4       : origin = 0x006A60, length = 0x000020     /* Enhanced Capture 4 registers */         ECAP5       : origin = 0x006A80, length = 0x000020     /* Enhanced Capture 5 registers */         ECAP6       : origin = 0x006AA0, length = 0x000020     /* Enhanced Capture 6 registers */         EQEP1       : origin = 0x006B00, length = 0x000040     /* Enhanced QEP 1 registers */EQEP2       : origin = 0x006B40, length = 0x000040     /* Enhanced QEP 2 registers */   GPIOCTRL    : origin = 0x006F80, length = 0x000040     /* GPIO control registers */GPIODAT     : origin = 0x006FC0, length = 0x000020     /* GPIO data registers */GPIOINT     : origin = 0x006FE0, length = 0x000020     /* GPIO interrupt/LPM registers */SYSTEM      : origin = 0x007010, length = 0x000020     /* System control registers */SPIA        : origin = 0x007040, length = 0x000010     /* SPI-A registers */SCIA        : origin = 0x007050, length = 0x000010     /* SCI-A registers */XINTRUPT    : origin = 0x007070, length = 0x000010     /* external interrupt registers */ADC         : origin = 0x007100, length = 0x000020     /* ADC registers */SCIB        : origin = 0x007750, length = 0x000010     /* SCI-B registers */SCIC        : origin = 0x007770, length = 0x000010     /* SCI-C registers */I2CA        : origin = 0x007900, length = 0x000040     /* I2C-A registers */CSM_PWL     : origin = 0x33FFF8, length = 0x000008     /* Part of FLASHA.  CSM password locations. */PARTID      : origin = 0x3D7E80, length = 0x000001
}SECTIONS
{PieVectTableFile : > PIE_VECT,   PAGE = 1/*** Peripheral Frame 0 Register Structures ***/DevEmuRegsFile    : > DEV_EMU,     PAGE = 1FlashRegsFile     : > FLASH_REGS,  PAGE = 1CsmRegsFile       : > CSM,         PAGE = 1AdcMirrorFile     : > ADC_MIRROR,  PAGE = 1 XintfRegsFile     : > XINTF,       PAGE = 1CpuTimer0RegsFile : > CPU_TIMER0,  PAGE = 1CpuTimer1RegsFile : > CPU_TIMER1,  PAGE = 1CpuTimer2RegsFile : > CPU_TIMER2,  PAGE = 1  PieCtrlRegsFile   : > PIE_CTRL,    PAGE = 1     DmaRegsFile       : > DMA,         PAGE = 1 /*** Peripheral Frame 3 Register Structures ***/McbspaRegsFile    : > MCBSPA,      PAGE = 1McbspbRegsFile    : > MCBSPB,      PAGE = 1/*** Peripheral Frame 1 Register Structures ***/ECanaRegsFile     : > ECANA,       PAGE = 1ECanaLAMRegsFile  : > ECANA_LAM    PAGE = 1   ECanaMboxesFile   : > ECANA_MBOX   PAGE = 1ECanaMOTSRegsFile : > ECANA_MOTS   PAGE = 1ECanaMOTORegsFile : > ECANA_MOTO   PAGE = 1ECanbRegsFile     : > ECANB,       PAGE = 1ECanbLAMRegsFile  : > ECANB_LAM    PAGE = 1   ECanbMboxesFile   : > ECANB_MBOX   PAGE = 1ECanbMOTSRegsFile : > ECANB_MOTS   PAGE = 1ECanbMOTORegsFile : > ECANB_MOTO   PAGE = 1EPwm1RegsFile     : > EPWM1        PAGE = 1   EPwm2RegsFile     : > EPWM2        PAGE = 1   EPwm3RegsFile     : > EPWM3        PAGE = 1   EPwm4RegsFile     : > EPWM4        PAGE = 1   EPwm5RegsFile     : > EPWM5        PAGE = 1   EPwm6RegsFile     : > EPWM6        PAGE = 1ECap1RegsFile     : > ECAP1        PAGE = 1   ECap2RegsFile     : > ECAP2        PAGE = 1   ECap3RegsFile     : > ECAP3        PAGE = 1   ECap4RegsFile     : > ECAP4        PAGE = 1ECap5RegsFile     : > ECAP5        PAGE = 1   ECap6RegsFile     : > ECAP6        PAGE = 1EQep1RegsFile     : > EQEP1        PAGE = 1   EQep2RegsFile     : > EQEP2        PAGE = 1               GpioCtrlRegsFile  : > GPIOCTRL     PAGE = 1GpioDataRegsFile  : > GPIODAT      PAGE = 1GpioIntRegsFile   : > GPIOINT      PAGE = 1/*** Peripheral Frame 2 Register Structures ***/SysCtrlRegsFile   : > SYSTEM,      PAGE = 1SpiaRegsFile      : > SPIA,        PAGE = 1SciaRegsFile      : > SCIA,        PAGE = 1XIntruptRegsFile  : > XINTRUPT,    PAGE = 1AdcRegsFile       : > ADC,         PAGE = 1ScibRegsFile      : > SCIB,        PAGE = 1ScicRegsFile      : > SCIC,        PAGE = 1I2caRegsFile      : > I2CA,        PAGE = 1/*** Code Security Module Register Structures ***/CsmPwlFile        : > CSM_PWL,     PAGE = 1PartIdRegsFile    : > PARTID,      PAGE = 1
}

Source目录下添加这个：

DSP28xxx_SectionCopy_nonBIOS.asm

 .ref _c_int00.global copy_sections.global _cinit_loadstart, _cinit_runstart, _cinit_size.global _const_loadstart, _const_runstart, _const_size.global _econst_loadstart, _econst_runstart, _econst_size.global _pinit_loadstart, _pinit_runstart, _pinit_size.global _switch_loadstart, _switch_runstart, _switch_size.global _text_loadstart, _text_runstart, _text_size***********************************************************************
* Function: copy_sections
*
* Description: Copies initialized sections from flash to ram
***********************************************************************.sect "copysections"copy_sections:MOVL XAR5,#_const_size               ; Store Section Size in XAR5MOVL ACC,@XAR5                     ; Move Section Size to ACCMOVL XAR6,#_const_loadstart           ; Store Load Starting Address in XAR6MOVL XAR7,#_const_runstart         ; Store Run Address in XAR7LCR  copy                            ; Branch to CopyMOVL XAR5,#_econst_size             ; Store Section Size in XAR5MOVL ACC,@XAR5                     ; Move Section Size to ACCMOVL XAR6,#_econst_loadstart      ; Store Load Starting Address in XAR6MOVL XAR7,#_econst_runstart            ; Store Run Address in XAR7LCR  copy                            ; Branch to CopyMOVL XAR5,#_pinit_size              ; Store Section Size in XAR5MOVL ACC,@XAR5                     ; Move Section Size to ACCMOVL XAR6,#_pinit_loadstart           ; Store Load Starting Address in XAR6MOVL XAR7,#_pinit_runstart         ; Store Run Address in XAR7LCR  copy                            ; Branch to Copy MOVL XAR5,#_switch_size                ; Store Section Size in XAR5MOVL ACC,@XAR5                     ; Move Section Size to ACCMOVL XAR6,#_switch_loadstart      ; Store Load Starting Address in XAR6MOVL XAR7,#_switch_runstart            ; Store Run Address in XAR7LCR  copy                            ; Branch to CopyMOVL XAR5,#_text_size               ; Store Section Size in XAR5MOVL ACC,@XAR5                     ; Move Section Size to ACCMOVL XAR6,#_text_loadstart            ; Store Load Starting Address in XAR6MOVL XAR7,#_text_runstart          ; Store Run Address in XAR7LCR  copy                            ; Branch to CopyMOVL XAR5,#_cinit_size              ; Store Section Size in XAR5MOVL ACC,@XAR5                     ; Move Section Size to ACCMOVL XAR6,#_cinit_loadstart           ; Store Load Starting Address in XAR6MOVL XAR7,#_cinit_runstart         ; Store Run Address in XAR7LCR  copy                            ; Branch to Copy LB _c_int00                            ; Branch to start of boot.asm in RTS librarycopy:   B return,EQ                         ; Return if ACC is Zero (No section to copy)RPT AL                              ; Copy Section From Load Address to|| PWRITE  *XAR7, *XAR6++          ; Run Addressreturn:LRETR                               ; Return.end

之后进行速度测试部分：

void beep()
{float a;            //1float b=2.843;//2a=sin(b);        //65a=b*3.14;       //6a=b+3.25;      //4a=b/0.98;      //235b=a*b;          //4GpioDataRegs.GPCSET.bit.GPIO64=1;//2GpioDataRegs.GPCCLEAR.bit.GPIO64=1;//1GpioDataRegs.GPCDAT.bit.GPIO64=1;//1GpioDataRegs.GPCTOGGLE.bit.GPIO64=1;//1
}

全程序在RAM中运行，仅仅使用了2.41us，三角函数的部分有较大的速度提升。

备注：

1、使用memory allocation查看内存分配情况，与CMD文件对应。

2、程序的运行时间，使用RUN---CLOCK----ENABLE开启查看

右下角即为运行到某点使用的时钟周期数，可以使用reset重新计时。