RM0440 Rev 4 1265/2126
RM0440 General-purpose timers (TIM2/TIM3/TIM4/TIM5)
1343
The dithering mode is also available in center-aligned PWM mode (CMS bits in TIMx_CR1
register are not equal to '00'). In this case, the dithering pattern is applied over 8 consecutive
PWM periods, considering the up and down counting phases as shown in the Figure 395
below.
Figure 395. Dithering effect on duty cycle in center-aligned PWM mode
Table 278 below shows how the dithering pattern is added in center-aligned PWM mode.
Table 277. CCR and ARR register change dithering pattern
LSB value
PWM period
12345678910111213141516
0000 ----------------
0001 +1---------------
0010 +1-------+1-------
0011 +1---+1---+1-------
0100 +1---+1---+1---+1---
0101 +1-+1-+1---+1---+1---
0110 +1 - +1 - +1 - - - +1 - +1 - +1 - - -
0111 +1 - +1 - +1 - +1 - +1 - +1 - +1 - - -
1000 +1-+1-+1-+1-+1-+1-+1-+1-
1001 +1+1+1 -+1 -+1 -+1 -+1 -+1 -+1 -
1010 +1 +1 +1 - +1 - +1 - +1 +1 +1 - +1 - +1 -
1011 +1+1+1 -+1+1+1 -+1+1+1 - +1 - +1 -
1100 +1 +1 +1 - +1 +1 +1 - +1 +1 +1 - +1 +1 +1 -
1101 +1 +1 +1 +1 +1 +1 +1 - +1 +1 +1 - +1 +1 +1 -
1110 +1+1+1+1+1+1+1 -+1+1+1+1+1+1+1 -
1111 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 -
MSv50904V1
No dithering Dithering up Dithering down