Si5351Aその９

　Si5351Aで３チャンネル出力の実験をしました。

　上がPLLA MS0の組み合わせで CLK0=1MHz

　中がPLLB MS1の組み合わせで CLK1=10MHz

　下がPLLB MS2の組み合わせで CLK2=5MHzの設定です。

　CLK0,CLK1,CLK2をPLLA,PLLBどちらに接続するかは、レジスタ16,17,18のビット5で設定します。

　ビット5=0 で PLLAに、 1でPLLBも接続されます。

　テストしたスケッチです。スケッチサイズは、約4KBです。（まだ中途半端ですが、参考までに）

#include <Wire.h>

#define  Si5351A_ADDR  0x60
#define MSNA_ADDR   26
#define MSNB_ADDR   34
#define MS0_ADDR    42
#define MS1_ADDR    50
#define MS2_ADDR    58
#define CLK0_CTRL   16
#define CLK1_CTRL   17
#define CLK2_CTRL   18
#define OUTPUT_CTRL  3
#define XTAL_LOAD_C 183
#define PLL_RESET  177
uint32_t frequency;
const uint32_t XtalFreq = 25000000;

uint32_t P1;
uint32_t P2;
uint32_t P3;
uint32_t PllFreq;
uint32_t l;
float f;
uint8_t mult;
uint32_t num;
uint32_t denom;
uint32_t divider;
char  PLL;
uint8_t PLL_ADDR;
uint8_t MS_ADDR;

void setup(){
  Wire.begin();       // Arduino is Master
  Si5351_init();      //Si5351Aの初期化
 
//PLLA=900MHz,CLK0=1MHz
  frequency = 1000000;
  divider = 900000000 / frequency;
  if (divider % 2) divider--;
  PLL_Set('A',frequency,divider);
  Si5351_write(CLK0_CTRL,0x4F); //CLK0 Sorce PLLA
  MS_Set(0,divider);

//PLLB=900MHz
  frequency = 10000000;
  divider = 900000000 / frequency;
  if (divider % 2) divider--;
  PLL_Set('B',frequency,divider);
//CLK1=10MHz
  Si5351_write(CLK1_CTRL,0x6F); //CLK1 Sorce PLLB
  MS_Set(1,divider);
//CLK2=5MHz
  Si5351_write(CLK2_CTRL,0x6F); //CLK2 Sorce PLLB
  divider=divider*2;
  MS_Set(2,divider);
}

void loop(){

}

//Si5351のレジスタに１バイトデータを書き込む。
void Si5351_write(byte Reg , byte Data)
{
  Wire.beginTransmission(Si5351A_ADDR);
  Wire.write(Reg);
  Wire.write(Data);
  Wire.endTransmission();
}

//Si5351Aの初期化
void Si5351_init(){
  Si5351_write(OUTPUT_CTRL,0xFF);   //Disable Output
  Si5351_write(CLK0_CTRL,0x80);     //CLOCK0 Power down
  Si5351_write(CLK1_CTRL,0x80);     //CLOCK1 Power down
  Si5351_write(CLK2_CTRL,0x80);     //CLOCK2 Power down
  Si5351_write(XTAL_LOAD_C,0x80);   //Crystal Load Capasitance=8pF
  Si5351_write(PLL_RESET,0xA0);     //Reset PLLA and PLLB
  Si5351_write(CLK0_CTRL,0x4F);     //CLOCK0 Power up
  Si5351_write(CLK1_CTRL,0x4F);     //CLOCK0 Power up
  Si5351_write(CLK2_CTRL,0x4F);     //CLOCK0 Power up 
  Si5351_write(OUTPUT_CTRL,0xF8);   //Enable CLOCK0,CLOCK1,CLOCK2
}

//PLLの設定
void PLL_Set(char Pll,uint32_t Freq,uint32_t Div){
  PllFreq = Div * Freq;
  mult = PllFreq / XtalFreq;
  l = PllFreq % XtalFreq;
  f = l;
  f *= 1048575;
  f /= XtalFreq;
  num = f;
  denom = 1048575;
 
  P1 = (uint32_t)(128 * ((float)num /(float)denom));
  P1 = (uint32_t)(128 * (uint32_t)(mult) + P1 - 512);
  P2 = (uint32_t)(128 * ((float)num / (float)denom));
  P2 = (uint32_t)(128 * num -denom * P2);
  P3=denom;

  if (Pll == 'A')
  {
    PLL_ADDR = MSNA_ADDR;
  }else
  {
    PLL_ADDR = MSNB_ADDR;
  }
  Parameter_write(PLL_ADDR,P1,P2,P3);
 }

//MultiSynth（分周器）のセット
void MS_Set(uint8_t MS_No,uint32_t Div){
  P1 = 128 * Div - 512;
  P2 = 0;
  P3 = 1;
  switch(MS_No){
    case 0:
      MS_ADDR = MS0_ADDR;
    break;
    case 1:
      MS_ADDR = MS1_ADDR;
    break;
    case 2:
      MS_ADDR = MS2_ADDR;
      break;
    default:
      MS_ADDR = MS0_ADDR;
  }
  Parameter_write(MS_ADDR,P1,P2,P3); 
}

//レジスタにパラメータP1,P2,P3を書き込む。
 void Parameter_write(uint8_t REG_ADDR,uint32_t Pa1,uint32_t Pa2,uint32_t Pa3)
{
  Si5351_write(REG_ADDR + 0,(Pa3 & 0x0000FF00) >> 8);
  Si5351_write(REG_ADDR + 1,(Pa3 & 0x000000FF));
  Si5351_write(REG_ADDR + 2,(Pa1 & 0x00030000) >> 16);
  Si5351_write(REG_ADDR + 3,(Pa1 & 0x0000FF00) >> 8);
  Si5351_write(REG_ADDR + 4,(Pa1 & 0x000000FF));
  Si5351_write(REG_ADDR + 5,((Pa3 & 0x000F0000) >> 12) | ((Pa2 & 0X000F0000) >> 16));
  Si5351_write(REG_ADDR + 6,(Pa2 & 0x0000FF00) >> 8);
  Si5351_write(REG_ADDR + 7,(Pa2 & 0x000000FF)); 
}