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FUJITSU MB91460 SERIES FR60 User Manual

Page 277

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261

Chapter 18 Timebase Counter

7.Q&A

7.2 How do I set the oscillation stabilization wait time without generating it

automatically?

The settings described below for various cases are required.

7.3 What is the clear timing for the timebase counter?

• The timebase counter is only cleared automatically by INIT pin input.

The timebase counter automatically starts counting after being cleared.

• The timebase counter can also be cleared by software.

See “

Chapter 19 Timebase Timer (Page No.263)

” for details.

State (before

transition)

Oscillation

Condition (after

transition)

Is oscillation

stabilization wait

required?

To set the oscillation

stabilization wait time

PLL

Main

Sub

Wait time after power on

Ч

Ч

Ч

Operation after INIT
signal input defaults to
main clock (1/2)
(Initial value)

Main clock
oscillation
stabilization wait
is required

As the automatic oscillation
stabilization wait (minimum
value) is too short, the width of
the INIT pin must be sufficient
to provide the stabilization time.

Subclock operation
(main clock halted)

Ч

Ч

O

Sub sleep, sub stop
(main clock halted)

Ч

Ч

O

Main clock oscillation
stabilization wait

Ч

Ч

O/

×

State (before

transition)

Oscillation

Main clock

oscillation enabled

Is oscillation

stabilization wait

required?

To set the oscillation

stabilization wait time

PLL

Main

Sub

Subclock operation
(main clock halted)

Ч

Ч

O

Main clock running

Main clock
oscillation
stabilization wait
is required

Using the main clock oscillation
stabilization wait timer to
generate the time is
recommended.

State (before

transition)

Oscillation

Main PLL running

and enabled

Is oscillation

stabilization wait

required?

To set the oscillation

stabilization wait time

PLL

Main

Sub

Subclock running (main
clock running)

×

O

O

Start main PLL
oscillation/
Change PLL
multiplier setting

Main PLL lock
wait required

Using the timebase timer to
generate the main PLL lock wait
time is recommended.

Main clock (1/2) running

×

O

O

O: Oscillation running,
×: Oscillation halted