điều chế độ rộng xung ra sin (SPWM)

[HYknight]

Chào các anh !
Bảng sin em lập như hướng dấn của anh Nam, Pic em dùng là 16F886, Fpwm = 20KHz
Nhưng không hiểu tại sao không thể chạy đúng
Nếu em dùng chương trình này cho Pic18 thì ok
Hay có điều gì về PWM của Pic16 mà em chưa đọc kĩ
Mong các anh giải thích giùm
Đây là chương trình của em :

#include <16f886.h>
#fuses  HS,NOWDT,NOPROTECT,NOLVP
#Device ADC = 10
#use    Delay(clock=20000000)

long Const Table_sin[400] =
{
500,507,515,523,531,539,547,554,562,570,578,585,593,601,609,616,624,631,639,647
,654,661,669,676,684,691,698,705,712,719,726,733,740,747,754,761,767,774,781,787
,793,800,806,812,818,824,830,836,842,847,853,859,864,869,875,880,885,890,895,899,
904,909,913,917,922,926,930,934,938,941,945,949,952,955,958,961,964,967,970,973,975,977
,980,982,984,986,987,989,991,992,993,995,996,996,997,998,999,999,999,999,100,999,
999,999,999,998,997,996,996,995,993,992,991,989,987,986,984,982,980,977,975,973,970
,967,964,961,958,955,952,949,945,941,938,934,930
,926,922,917,913,909,904,899,895,890,885,880,875,869,864,859,853,847,842,836,830,824,
818,812,806,800,793,787,781,774,767,761,754,747,740,733,726,719,712,705,698,691,684,
676,669,661,654,647,639,631,624,616,609,601,593,585
,578,570,562,554,547,539,531,523,515,507,500,492,484,476,468,460,452,445,437,429,421,
414,406,398,390,383,375,368,360,352,345,338,330,323,315,308,301,294,287,280,273,266,
259,252,245,238,232,225,218,212,206,199,193
,187,181,175,169,163,157,152,146,140,135,130,124,119,114,109,104,100,95,90,86,82,77,
73,69,65,61,58,54,50,47,44,41,38,35,32,29,26,24,22,19,17,15,13,12,10,8,7,6,4,3,3
,2,1,0,0,0,0,0,0,0,0,0,1,2,3,3,4,6,7,8,10,12,13,15,17,19,22,24,26,29,32,35,38,41,
44,47,50,54,58,61,65,69,73,77,82,86,90,95,100,104,109,114,119,124,130
,135,140,146,152,157,163,169,175,181,187,193,199,206,212,218,225,232,238,245,252
,259,266,273,280,287,294,301,308,315,323,330,338,345,352
,360,368,375,383,390,398,406,414,421,429,437,445,452,460,468,476,484,492};

Unsigned Int16 Index;

Void Main()
      {  
         Set_Tris_A(0x0F);
         Set_Tris_B(0x00); 
         Set_Tris_C(0X02);

         Setup_Timer_2(T2_DIV_BY_1, 249, 1);
         Setup_ccp1(CCP_PWM);
         Index = 0; 
         
         While(1)
          {
              Set_pwm1_duty(Table_sin[index]);
              Index++;
              if (index > 399 ) 
                {
                  Index=0;
                }
          }
         
      }