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Chapter 22 main oscillation stabilisation timer, Overview, Features – FUJITSU MB91460 SERIES FR60 User Manual

Page 305: Chapter 22 main oscillation stabilisation

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Chapter 22 Main Oscillation Stabilisation Timer

1.Overview

Chapter 22 Main Oscillation Stabilisation Timer

1. Overview

The main clock oscillation stabilisation timer is a 23-bit counter that counts the main clock. This timer does not
affect the selection of clock source operated by MCU/dividing setting.

This timer is mainly used for acquiring main clock oscillation stability wait time to resume main clock oscillation
after the main clock oscillation has been stopped (OSCCR.OSCDS1=1) while the subclock is being operated.

In addition, this timer is best suited for interval timers or system clocks for real time OS.

2. Features

• Type

: 23-bit free run counter

• Quantity

: 1

• Clock source

: Main clock (source oscillation) --- Period = 1/F

CL-MAIN

• Interval time

: 3 types

Period =2

12

/F

CL-MAIN

, 2

17

/F

CL-MAIN

, 2

23

/F

CL-MAIN

,

(1.0ms, 32.7ms, 2s / main clock 4MHz)

• Cause of timer clear: (Software, overflow, reset (INIT))

• Operation start/stop : Can be operated/stopped by the software.

• Interrupt

: Main clock oscillation stability wait interrupt (Interval interrupt)

• Count value

: Cannot read/write. (Clear only)

Main clock
(Source oscillation)

Up-counter

Selector

Interrupt