20.3.2.7 Frequency Generation (FRG)
Frequency generation (see
Figure 20.17 TIMER/WTIMER Up-count Frequency Generation on page 664
) can be achieved in compare
mode by:
• Setting the counter in up-count mode
• Enabling buffering of the TOP value.
• Setting the CC channels overflow action to toggle
0
TIMERn_TOP
TIMERn_CCx_CCV
Figure 20.17. TIMER/WTIMER Up-count Frequency Generation
The output frequency is given by
Figure 20.18 TIMER/WTIMER Up-count Frequency Generation Equation on page 664
f
FRG
= f
HFPERCLK
/ ( 2^(PRESC + 1) x (TOP + 1) x 2)
Figure 20.18. TIMER/WTIMER Up-count Frequency Generation Equation
The figure below provides cycle accurate timing and event generation information for frequency generation.
0
TIMERn_TOP =
TIMERn_CCx_CCV
1
2
3
4
TIMERn_CCx
Figure 20.19. TIMER/WTIMER Up-count Frequency Generation Detail
20.3.2.8 Pulse-Width Modulation (PWM)
In PWM mode, TIMERn_CCx_CCV is buffered to avoid glitches in the output. The settings in the Compare Output Action configuration
bits are ignored in PWM mode and PWM generation is only supported for up-count and up/down-count mode.
Reference Manual
TIMER/WTIMER - Timer/Counter
silabs.com
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