RV-3049 datasheet(30/65 Pages) MICROCRYSTAL

30 / 65 page

Micro Crystal

DTCXO Temperature Compensated Real Time Clock / Calendar Module

RV-3049

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Example Countdown Timer function with Timer in Auto Reload mode

In this example, the Countdown Timer is set to Automatic Reload Mode, the Countdown Timer value is set = “3”.

Automatic reload of the countdown value ,n’ requires 1 additional Timer Source Clock. This additional timer

source clock has no effect on the first Timer period but it has to be taken into account since it results in a Timer

duration of ,n+1’ for subsequent timer periods. The Interrupt signal ( INT ) is cleared by clearing the Timer Flag

“TF” = “0”.

Countdown Timer

Value

INT

TAR

Auto

Reload

Timer Source

Clock Frequency

TD0 / TD1

TSC

Auto

Reload

n +1

TSC

Timer Source Clock Frequency TD0 / TD1 can only be modified when Timer is disabled “TE” = “0”

Countdown Timer value ,n’ in “Timer Low” and “Timer High” only can be modified when Timer “TE” = “0”

and Timer Auto Reload “TAR” = “0” are both disabled.

Duration of first Timer Period

Frequency

Clock

Source

The additional timer source clock for automatic reload of the countdown Timer value ,n’ has no effect on

the first Timer Period.

Timer Automatic Reload mode “TAR” requires one Timer Source Clock period for automatic reload of the

Countdown Timer value ,n’.

To reset Interrupt signal ( INT ), Timer Flag “TF” has to be cleared by writing = “0”.

When Countdown Timer is in automatic reload mode, one additional timer source clock has to be taken

into account since it results in a Timer duration of ,n+1’ for subsequent timer periods.

RV-3049 датащи(PDF) 30 Page - MICORO CRYSTAL SWITZERLAND