upd78f0114hgb-8es-a Renesas Electronics Corporation., upd78f0114hgb-8es-a Datasheet - Page 478

• Manufacturer Part Number: upd78f0114hgb-8es-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

478
Main Clock
Function
Oscillation
stabilization
time counter
status register
(OSTC)
Oscillation
stabilization
time select
register (OSTS)
Details of
Function
Waiting for the oscillation stabilization time is not required when the external RC
oscillation clock is selected as the high-speed system clock by the option byte.
Therefore, the CPU clock can be switched without reading the OSTC value.
After the above time has elapsed, the bits are set to 1 in order from MOST11
and remain 1.
If the STOP mode is entered and then released while the internal oscillation
clock is being used as the CPU clock, set the oscillation stabilization time as
follows.
• Desired OSTC oscillation stabilization time ≤ Oscillation stabilization time set
The wait time when STOP mode is released does not include the time after
STOP mode release until clock oscillation starts (“a” below) regardless of
whether STOP mode is released by RESET input or interrupt generation.
To set the STOP mode when the high-speed system clock is used as the CPU
clock, set OSTS before executing a STOP instruction.
Before setting OSTS, confirm with OSTC that desired oscillation stabilization
time has elapsed.
If the STOP mode is entered and then released while the internal oscillation
clock is being used as the CPU clock, set the oscillation stabilization time as
follows.
The wait time when STOP mode is released does not include the time after
STOP mode release until clock oscillation starts (“a” below) regardless of
whether STOP mode is released by RESET input or interrupt generation.
by OSTS
The oscillation stabilization time counter counts up to the oscillation
stabilization time set by OSTS. Note, therefore, that only the status up to the
oscillation stabilization time set by OSTS is set to OSTC after STOP mode is
released.
by OSTS
The oscillation stabilization time counter counts up to the oscillation
stabilization time set by OSTS. Note, therefore, that only the status up to the
oscillation stabilization time set by OSTS is set to OSTC after STOP mode is
released.
Desired OSTC oscillation stabilization time
APPENDIX D LIST OF CAUTIONS
User’s Manual U16961EJ4V0UD
Cautions
Oscillation stabilization time set
p. 103
p. 103
p. 103
p. 103
p. 104
p. 104
p. 104
p. 104
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