RM0312 datasheet(164/275 Pages) STMICROELECTRONICS

No. de pieza	RM0312

Descripción Electrónicos	STM8TL5xxx microcontroller family

PDF	275 Pages

Scroll/Zoom	100%

Fabricante Electrónico	STMICROELECTRONICS [STMicroelectronics]

Página de inicio	http://www.st.com

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164 / 275 page

8-bit basic timer (TIM4)

RM0312

164/275

DocID022352 Rev 3

18.4

TIM4 clock selection

The clock source for the timer is the internal clock (fMASTER). It is connected directly to the

CK_PSC clock that feeds the prescaler driving the counter clock CK_CNT.

Prescaler

The prescaler implementation is as follows:

•

The TIM4 prescaler is based on a 16-bit counter controlled through a 4-bit register (in

TIM4_PSCR register). It can be changed on the fly as this control register is buffered. It

can divide the counter clock frequency by any power of 2 from 1 to 32768.

The counter clock frequency is calculated as follows:

fCK_CNT = fCK_PSC/2(PSCR[3:0])

The prescaler value is loaded through a preload register. The shadow register, which

contains the current value to be used is loaded as soon as the LS Byte has been written.

Read operations to the TIM4_PSCR registers access the preload registers, so no special

care needs to be taken to read them.

RM0312 Datasheet(PDF) 164 Page - STMicroelectronics