sinusoidal PWM

[bwaxing]

hellow Henrik,
thanx for the tips, i've re-worked my sine table,also i've include the code for accuracy although i'm not sure if i've place it in a right place!
For a 4MHz xtal and TMR1 prescaler of 1 i reload the T1 with the value 64980 to get 50Hz and it's what m getting on the scope.
Also TMR2 with prescaler of 4 is loaded with 117 for the interrupt to be generated every 556us(256-(556/(4*0.25*4))
But the problem is that the waveform i'm getting on the scope is not smooth at all....Simulation results..pdf

code:

define OSC 4
 
;*****************VARIABLE DECLARATION******************************************
wsave   VAR BYTE    $70     SYSTEM      ' alternate save location for W 
wsave1  VAR BYTE    $A0     SYSTEM      ' location for W if in bank1
wsave2  VAR BYTE    $120    SYSTEM      ' location for W if in bank2
wsave3  VAR BYTE    $1A0    SYSTEM      ' location for W if in bank3
STEPCOUNT var byte                      'Define stepcount as byte type variable
stepcount = 36
 
;**************SETTING THE REGISTERS WITH APPROPIATE BIT DEFINITION************* 
ADCON0 = %00000000
ADCON1 = %00000000  ;all anolog output
trisb = %11111111   ;define porta as input
trisc = %11111011   ;make ccp1/portc.2 an output pin
trisa = %11111111   ;define porta as input
TMR2 = 117
PR2 = 13          ;set for 18Khz HPWM(=36 steps*10 times*50hz)        
CCP1CON = %000001100       ;set to pwm mode
T2CON=%00000110           ;enable timer2 and set timer2 prescaler value of 1:4
 
;****************A sine lookup table in an array********************************
sineval var byte[36]
sineval[0] = 128
sineval[1] = 148
sineval[2] = 167
sineval[3] = 185
sineval[4] = 201
sineval[5] = 215
sineval[6] = 227
sineval[7] = 235
sineval[8] = 240
sineval[9] = 242
sineval[10] = 240
sineval[11] = 235
sineval[12] = 227
sineval[13] = 215
sineval[14] = 201
sineval[15] = 185
sineval[16] = 167
sineval[17] = 148
sineval[18] = 128
sineval[19] = 108
sineval[20] = 89
sineval[21] = 71
sineval[22] = 55
sineval[23] = 41
sineval[24] = 29
sineval[25] = 21
sineval[26] = 16
sineval[27] = 14
sineval[28] = 16
sineval[29] = 21
sineval[30] = 29
sineval[31] = 41
sineval[32] = 55
sineval[33] = 71
sineval[34] = 89
sineval[35] = 108
 
timerone var word 
 
INCLUDE "DT_INTS-14.bas"     ; Base Interrupt System
 
;********Define INT_Handler as ISR********************************************** 
ASM
 
INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler   TMR1_INT,   _sine,   ASM,  yes
    endm
    INT_CREATE               ; Creates the interrupt processor
ENDASM
 
T1CON = %000001    ; Prescaler = 1, TMR1ON          
TMR1L = 255    
TMR1H = 254
@   INT_ENABLE  TMR1_INT     ; Enable Timer 1 Interrupts  
timerone = 64980           ;gives about 50 hz sine 
Main:
        pause 5
 
GOTO Main
 
'---[TMR1_INT - interrupt handler]------------------------------------------
 
'accuracy thing
TimerShadow VAR WORD
T1CON.0 = 0  'Stop TMR1
TimerShadow.HighByte = TMR1H
TimerShadow.LowByte = TMR1L
TimerShadow = TimerShadow + Timerone
TMR1H = TimerShadow.HighByte
TMR1L = TimerShadow.LowByte
T1CON.0 = 1  'Restart TMR1
sine:
    TMR1L = timerone.byte0
    TMR1H = timerone.byte1     
    CCPR1L = sineval[STEPCOUNT]>>1 
    stepcount = stepcount -1
    if stepcount = 0 then stepcount = 36
@    INT_RETURN

where i'm wrong in the code? are the calculations above correct?