# 06.02_DSP-开方  

## 测试步骤  
使用硬件dsp进行除法计算
## 实测数据  
|a|DSP_Sqrt(a)|err|  
|-|-|-|  
|0 (0x00000000)|0|0|  
|1 (0x00000001)|1|0|  
|10 (0x0000000a)|3|0|  
|100 (0x00000064)|10|0|  
|1000 (0x000003e8)|31|0|  
|10000 (0x00002710)|100|0|  
|32767 (0x00007fff)|181|0|  
|65535 (0x0000ffff)|255|0|  
|65536 (0x00010000)|256|0|  
|65536 (0x00010000)|256|0|  
|131072 (0x00020000)|362|0|  
|262144 (0x00040000)|512|0|  
|524288 (0x00080000)|724|0|  
|1048576 (0x00100000)|1024|0|  
|2097152 (0x00200000)|1448|0|  
|4194304 (0x00400000)|2048|0|  
|8388608 (0x00800000)|2896|0|  
|16777216 (0x01000000)|4096|0|  
|33554432 (0x02000000)|5792|0|  
|67108864 (0x04000000)|8192|0|  
|134217728 (0x08000000)|11585|0|  
|268435456 (0x10000000)|16384|0|  
|536870912 (0x20000000)|23170|0|  
|1073741824 (0x40000000)|32768|0|  
|2147483648 (0x80000000)|46340|0|  
|1 (0x00000001)|1|0|  
|3 (0x00000003)|1|0|  
|7 (0x00000007)|2|0|  
|15 (0x0000000f)|3|0|  
|31 (0x0000001f)|5|0|  
|63 (0x0000003f)|7|0|  
|127 (0x0000007f)|11|0|  
|255 (0x000000ff)|15|0|  
|511 (0x000001ff)|22|0|  
|1023 (0x000003ff)|31|0|  
|2047 (0x000007ff)|45|0|  
|4095 (0x00000fff)|63|0|  
|8191 (0x00001fff)|90|0|  
|16383 (0x00003fff)|127|0|  
|32767 (0x00007fff)|181|0|  
|65535 (0x0000ffff)|255|0|  
|8191 (0x00001fff)|90|0|  
|16383 (0x00003fff)|127|0|  
|32767 (0x00007fff)|181|0|  
|65535 (0x0000ffff)|255|0|  
|131071 (0x0001ffff)|362|0|  
|262143 (0x0003ffff)|511|0|  
|524287 (0x0007ffff)|724|0|  
|1048575 (0x000fffff)|1023|0|  
|2097151 (0x001fffff)|1448|0|  
|4194303 (0x003fffff)|2047|0|  
|8388607 (0x007fffff)|2896|0|  
|16777215 (0x00ffffff)|4095|0|  
|33554431 (0x01ffffff)|5792|0|  
|67108863 (0x03ffffff)|8191|0|  
|134217727 (0x07ffffff)|11585|0|  
|268435455 (0x0fffffff)|16383|0|  
|536870911 (0x1fffffff)|23170|0|  
|1073741823 (0x3fffffff)|32767|0|  
|2147483647 (0x7fffffff)|46340|0|  
|4294967295 (0xffffffff)|65535|0|  
time = 107  

## 参考代码  
06.02_DSP_Sqrt.c
```c
/**
 * @brief DSP-开方
 * @details 使用硬件dsp进行除法计算
 */
#include "lks32mc09x_dsp.h"
#include "lks32mc09x_timer.h"
volatile int a = 10000;
volatile int y;
volatile int time;
void Timer0_Init(void);
/**
 * @brief 主函数，用于测试HSI时钟输出及GPIO翻转
 */
int main(void)
{
    DSP_Init();
    Timer0_Init();

    while (1)
    {
        TIMER_StatisticsStart(TIMER0);
        y = DSP_Sqrt(a);
        time = TIMER_StatisticsStop(TIMER0);
    }
}
/**
 * @brief 配置定时器0，用来统计除法执行时间
 */
void Timer0_Init(void)
{
    TIMER_TimerInitTypeDef TIMER_InitStruct;
    TIMER_StructInit(&TIMER_InitStruct);

    TIMER_InitStruct.EN = 1;
    TIMER_InitStruct.TH = 0xffff;

    TIMER_Init(TIMER0, &TIMER_InitStruct);
    TIMER_Enable(TIMER0);
}
#include "math.h"
```

## 使用到的库函数  
库函数部分代码
```c
#define REG_RESET(reg,mask) reg &= ~(mask)
#define REG_SET(reg,mask) reg |= (mask)
#define REG_WRITE(reg,mask) reg = (mask)
#define SYS0 ((SYS_TypeDef *)(SYS_BASE))
#define SYS_MODULE_DSP0 BIT17
#define SYS_MODULE_TIMER0 BIT4
#define SYS_MODULE_TIMER1 BIT5
#define SYS_MODULE_TIMER2 BIT6
#define TIMER0 ((TIMER_TypeDef *)TIMER0_BASE)
#define TIMER1 ((TIMER_TypeDef *)TIMER1_BASE)
#define TIMER2 ((TIMER_TypeDef *)TIMER2_BASE)
/**
 * @brief Timer初始化结构体
 */
typedef struct TIMER_TimerInitTypeDef {
    uint8_t EN;
    uint32_t CAP1_CLR_EN;
    uint32_t CAP0_CLR_EN;
    uint32_t ONE_TRIG;
    uint32_t CENTER;
    uint32_t DIR;
    uint32_t ClockDiv;
    uint32_t ETON;
    uint32_t GATE_EN;
    uint32_t RL_EN;
    uint32_t XCLK_EN;
    uint32_t SRC1;
    uint32_t CH1Output;
    uint32_t CH1_WorkMode;
    uint32_t CH1_FE_CAP_EN;
    uint32_t CH1_RE_CAP_EN;
    uint32_t SRC0;
    uint32_t CH0Output;
    uint32_t CH0_WorkMode;
    uint32_t CH0_FE_CAP_EN;
    uint32_t CH0_RE_CAP_EN;
    uint32_t TH;
    uint32_t CNT;
    uint32_t CHN0;
    uint32_t CHN1;
    uint32_t EVT;
    uint32_t FLT;
    uint32_t IE;
    uint32_t CMP0_TRIGGER_MODE;
    uint32_t CMP1_TRIGGER_MODE;
    uint32_t SHADOW;
    uint32_t CH1_DEFAULT;
    uint32_t CH0_DEFAULT;
    uint32_t HALT_PRT;
    uint32_t FAIL_SEL;
    uint32_t FAIL_POL;
    uint32_t FAIL_EN;
    uint32_t MOE;
};
/**
 * @brief Timer初始化
 * @param TIMERx Timer实例指针
 * @param TIMER_InitStruct Timer初始化结构体指针
 */
void TIMER_Init(TIMER_TypeDef *TIMERx, TIMER_TimerInitTypeDef *TIMER_InitStruct)
{
    uint32_t th = TIMER_InitStruct->TH;
    TIMER_Enable(TIMERx);
    if (TIMERx != TIMER2) // 只有timer2是32位定时器
    {
        if (th > 0xffff)
        {
            th = 0xffff;
        }
        else
        {
            __NOP();
        }
    }
    else
    {
        __NOP();
    }
    // 配置Timer寄存器
    TIMERx->CFG2 = (TIMER_InitStruct->EN << 15) |
                   (TIMER_InitStruct->ONE_TRIG << 9) |
                   (TIMER_InitStruct->CENTER << 8) |
                   (TIMER_InitStruct->DIR << 6) |
                   (TIMER_InitStruct->ClockDiv << 4) |
                   (TIMER_InitStruct->ETON << 3) |
                   (TIMER_InitStruct->GATE_EN << 2) |
                   (TIMER_InitStruct->RL_EN << 1) |
                   TIMER_InitStruct->XCLK_EN;

    TIMERx->CFG0 = (TIMER_InitStruct->CMP0_TRIGGER_MODE << 9) |
                   (TIMER_InitStruct->CAP0_CLR_EN << 8) |
                   (TIMER_InitStruct->SRC0 << 4) |
                   (TIMER_InitStruct->CH0Output << 3) |
                   (TIMER_InitStruct->CH0_WorkMode << 2) |
                   (TIMER_InitStruct->CH0_FE_CAP_EN << 1) |
                   (TIMER_InitStruct->CH0_RE_CAP_EN << 0);

    TIMERx->CFG1 = (TIMER_InitStruct->CMP1_TRIGGER_MODE << 9) |
                   (TIMER_InitStruct->CAP1_CLR_EN << 8) |
                   (TIMER_InitStruct->SRC1 << 4) |
                   (TIMER_InitStruct->CH1Output << 3) |
                   (TIMER_InitStruct->CH1_WorkMode << 2) |
                   (TIMER_InitStruct->CH1_FE_CAP_EN << 1) |
                   (TIMER_InitStruct->CH1_RE_CAP_EN << 0);

    TIMERx->CHN0 = TIMER_InitStruct->CHN0;
    TIMERx->CHN1 = TIMER_InitStruct->CHN1;
    TIMERx->TH   = th;
    TIMERx->CNT  = TIMER_InitStruct->CNT;
    TIMERx->EVT  = TIMER_InitStruct->EVT;
    TIMERx->FLT  = TIMER_InitStruct->FLT;
    TIMERx->IE   = TIMER_InitStruct->IE;

    TIMERx->IO = (TIMER_InitStruct->HALT_PRT << 7) |
                 (TIMER_InitStruct->CH0_DEFAULT << 8) |
                 (TIMER_InitStruct->CH1_DEFAULT << 9) |
                 (TIMER_InitStruct->MOE << 6) |
                 (TIMER_InitStruct->FAIL_SEL << 2) |
                 (TIMER_InitStruct->FAIL_POL << 1) |
                 (TIMER_InitStruct->FAIL_EN << 0);

    // 影子寄存器配置
    TIMERx->CFG2 |= (TIMER_InitStruct->SHADOW << 10);
}
/**
 * @brief Timer结构体初始化
 * @param TIMER_InitStruct Timer初始化结构体指针
 */
void TIMER_StructInit(TIMER_TimerInitTypeDef *TIMER_InitStruct)
{
    for (int i = 0; i < sizeof(TIMER_TimerInitTypeDef) / sizeof(uint32_t); i++)
    {
        ((uint32_t *)TIMER_InitStruct)[i] = 0;
    }
}
/**
 * @brief 使能Timer
 * @param TIMERx Timer实例指针
 */
void TIMER_Enable(TIMER_TypeDef *TIMERx)
{
    if (TIMERx == TIMER0)
    {
        SYS_ModuleClockCmd(SYS_MODULE_TIMER0, ENABLE);
    }
    else if (TIMERx == TIMER1)
    {
        SYS_ModuleClockCmd(SYS_MODULE_TIMER1, ENABLE);
    }
    else if (TIMERx == TIMER2)
    {
        SYS_ModuleClockCmd(SYS_MODULE_TIMER2, ENABLE);
    }
    else
    {
        __NOP();
    }
}
/**
 * @brief 初始化DSP模块
 *
 * 该函数用于初始化DSP模块，使其处于可用状态。
 */
void DSP_Init(void)
{
    SYS_ModuleClockCmd(SYS_MODULE_DSP0, ENABLE);
    SYS_SoftResetModule(SYS_MODULE_DSP0);
}
/**
 * @brief 数字模块时钟使能
 * @param nModule 模块编号
 * @param state 使能或禁用状态
 */
void SYS_ModuleClockCmd(uint32_t nModule, uint8_t state)
{
    REG_WRITE(SYS0->PROTECT, 0x7a83);
    if (state)
    {
        REG_SET(SYS0->CLK_FEN, nModule);
    }
    else
    {
        REG_RESET(SYS0->CLK_FEN, nModule);
    }
    REG_WRITE(SYS0->PROTECT, 0);
}
/**
 * @brief 计算平方根
 *
 * @param val 输入值
 * @return 平方根值
 */
uint16_t DSP_Sqrt(uint32_t val)
{
    DSP0_RAD = val;
    return DSP0_SQRT;
}
/**
 * @brief 软复位模块
 * @param nModule 模块编号
 */
void SYS_SoftResetModule(uint32_t nModule)
{
    REG_WRITE(SYS0->PROTECT, 0x7a83);
    REG_SET(SYS0->SFT_RST, nModule);
    REG_RESET(SYS0->SFT_RST, nModule); // 触发复位后需清除复位位
    REG_WRITE(SYS0->PROTECT, 0);
}
```
