CHAPTER 5 CLOCK GENERATORS
Preliminary User’s Manual U16898EJ1V0UD
74
Figure 5-12. Timing Chart of Default Start by Crystal/Ceramic Oscillator
V
DD
Crystal/ceramic
oscillator clock
PCC = 02H, PPCC = 02H
(a)
(b)
(c)
H
RESET
System clock
Internal reset
CPU clock
Option byte is read.
System clock is selected.
(Operation stops: 8/f
RL
+ 96/f
RH
)
Clock oscillation
stabilization
time
Note
Note The clock oscillation stabilization time for default start is selected by the option byte. For details, refer to
CHAPTER 17 OPTION BYTE. The oscillation stabilization time that elapses after the STOP mode is
released is selected by the oscillation stabilization time select register (OSTS).
Remark f
RL
: Low-speed Ring-OSC clock oscillation frequency
f
RH
: High-speed Ring-OSC clock oscillation frequency
(a) The internal reset signal is generated by the power-on clear function on power application, the option byte is
referenced after reset, and the system clock is selected.
(b) After high-speed Ring-OSC clock is generated, the option byte is referenced and the system clock is
selected. In this case, the crystal/ceramic oscillator clock is selected as the system clock.
(c) If the system clock is the crystal/ceramic oscillator clock, it starts operating as the CPU clock after clock
oscillation is stabilized. The wait time is selected by the option byte. For details, refer to CHAPTER 17
OPTION BYTE.
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