beautypg.com

FUJITSU F2MCTM-16LX User Manual

Page 206

background image

190

CHAPTER 11 TIMEBASE TIMER

Operation as Oscillation Stabilization Wait Time Timer

The timebase timer can be used as the oscillation stabilization wait time timer for the main clock and PLL

clock.

The oscillation stabilization wait time is the time elapsed from when the timebase timer counter increments

from "0" until the set oscillation stabilization wait time select bit overflows (carrying).

Table 11.5-1 shows clearing conditions and oscillation stabilization wait time of timebase timer.

Table 11.5-1 Clearing Conditions and Oscillation Stabilization Wait Time of Timebase

Timer (1/2)

Operation

Counter

clear

TBOF

clear

Oscillation stabilization wait time

Writing "0" to timebase timer
counter clear bit (TBTC: TBR)

Reset

Power-on reset

Transition to main clock mode after
oscillation stabilization wait time of
main clock completed

Watchdog reset

None

External reset
Low voltage detection reset
CPU operation detection reset
Clock supervisor reset

None

Software reset

None

Switching clock mode

Main clock

→ PLL clock

(CKSCR: MCS=1

→ 0)

Transition to PLL clock mode after
oscillation stabilization wait time of
PLL clock completed

Main clock

→ sub clock

(CKSCR: SCS=1

→ 0)

Transition to sub clock mode after
oscillation stabilization wait time of
sub clock completed

Sub clock

→ main clock

(CKSCR: SCS=0

→ 1)

Transition to main clock mode after
oscillation stabilization wait time of
main clock completed

Sub clock

→ PLL clock

(CKSCR: MCS=0, SCS=0

→ 1)

Transition to PLL clock mode after
oscillation stabilization wait time of
main clock completed

PLL clock

→ main clock

(CKSCR: MCS=0

→ 1)

None

PLL clock

→ sub clock

(CKSCR: MCS=0, SCS=1

→ 0)

None