MCBSTM32EXL Keil, MCBSTM32EXL Datasheet - Page 265

• Manufacturer Part Number: MCBSTM32EXL
• Description: BOARD EVALUATION FOR STM32F103ZE
• Manufacturer: Keil

Specifications of MCBSTM32EXL

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

RM0008
13.3.3
Figure 70. Counter timing diagram, Update event with ARPE=1 (counter overflow)
Repetition counter
Section 13.3.1: Time-base unit
respect to the counter overflows/underflows. It is actually generated only when the repetition
counter has reached zero. This can be useful when generating PWM signals.
This means that data are transferred from the preload registers to the shadow registers
(TIMx_ARR auto-reload register, TIMx_PSC prescaler register, but also TIMx_CCRx
capture/compare registers in compare mode) every N counter overflows or underflows,
where N is the value in the TIMx_RCR repetition counter register.
The repetition counter is decremented:
●
●
●
The repetition counter is an auto-reload type; the repetition rate is maintained as defined by
the TIMx_RCR register value (refer to
software (by setting the UG bit in TIMx_EGR register) or by hardware through the slave
mode controller, it occurs immediately whatever the value of the repetition counter is and the
repetition counter is reloaded with the content of the TIMx_RCR register.
At each counter overflow in upcounting mode,
At each counter underflow in downcounting mode,
At each counter overflow and at each counter underflow in center-aligned mode.
Although this limits the maximum number of repetition to 128 PWM cycles, it makes it
possible to update the duty cycle twice per PWM period. When refreshing compare
registers only once per PWM period in center-aligned mode, maximum resolution is
2xT
ck
, due to the symmetry of the pattern.
Auto-reload preload register
Auto-reload active register
Update interrupt flag (UIF)
Timer clock = CK_CNT
Update event (UEV)
Counter overflow
Counter register
Write a new value in TIMx_ARR
Doc ID 13902 Rev 9
describes how the update event (UEV) is generated with
CK_PSC
CEN
Figure
FD
FD
F7
71). When the update event is generated by
F8 F9 FA FB FC
Advanced-control timers (TIM1&TIM8)
36
35 34 33 32 31 30 2F
36
36
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