UPD78F0411GA-GAM-AX Datasheet, PDF (468/564 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 19 STANDBY FUNCTION
Cautions 1. To use the peripheral hardware that stops operation in the STOP mode, and the peripheral
hardware for which the clock that stops oscillating in the STOP mode after the STOP mode is
released, restart the peripheral hardware.
2. Even if “internal low-speed oscillator can be stopped by software” is selected by the option
byte, the internal low-speed oscillation clock continues in the STOP mode in the status before
the STOP mode is set. To stop the internal low-speed oscillator’s oscillation in the STOP mode,
stop it by software and then execute the STOP instruction.
3. To shorten oscillation stabilization time after the STOP mode is released when the CPU operates
with the high-speed system clock (X1 oscillation), temporarily switch the CPU clock to the
internal high-speed oscillation clock before the next execution of the STOP instruction. Before
changing the CPU clock from the internal high-speed oscillation clock to the high-speed system
clock (X1 oscillation) after the STOP mode is released, check the oscillation stabilization time
with the oscillation stabilization time counter status register (OSTC).
(2) STOP mode release
Figure 19-5. Operation Timing When STOP Mode Is Released (When Unmasked Interrupt
Request Is Generated)
STOP mode release
STOP mode
High-speed system
clock (X1 oscillation)
High-speed system
clock (external clock
input)
Internal high-speed
oscillation clock
High-speed system
clock (X1 oscillation)
is selected as CPU
clock when STOP
instruction is executed
High-speed system
clock (external clock
input) is selected as
CPU clock when STOP
instruction is executed
Internal high-speed
oscillation clock is
selected as CPU clock
when STOP instruction
is executed
Wait for oscillation accuracy
stabilization (86 to 361μs)
HALT status
(oscillation stabilization time set by OSTS)
High-speed system clock
Automatic selection
Wait^Note
High-speed system clock
Internal high-speed
oscillation clock
Wait^Note
High-speed system clock
Clock switched by software
Note
The wait time is as follows:
• When vectored interrupt servicing is carried out: 8 or 9 clocks
• When vectored interrupt servicing is not carried out: 2 or 3 clocks
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User’s Manual U18698EJ1V0UD