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CHAPTER 5 CLOCK GENERATOR
User’s Manual U19780EJ2V0UD
162
Table 5-5. CPU Clock Transition and SFR Register Setting Examples (3/5)
(6) CPU clock changing from high-speed system clock (C) to internal high-speed oscillation clock (B)
(Setting sequence of SFR registers)
Setting Flag of SFR Register
Status Transition
RSTOP RSTS MCM0
(C)
→
(B)
0
Confirm this flag is 1.
0
Unnecessary if the CPU is operating
with the internal high-speed oscillation clock
(7) CPU clock changing from high-speed system clock (C) to subsystem clock (D)
Note
Note
The 78K0/KB2-A is not provided with a subsystem clock.
(Setting sequence of SFR registers)
Setting Flag of SFR Register
Status Transition
OSCSELS
Waiting for Oscillation
Stabilization
CSS
(C)
→
(D)
1
Necessary
1
Unnecessary if the CPU is operating
with the subsystem clock
(8) CPU clock changing from subsystem clock (D) to internal high-speed oscillation clock (B)
Note
The 78K0/KB2-A is not provided with a subsystem clock.
(Setting sequence of SFR registers)
Setting Flag of SFR Register
Status Transition
RSTOP RSTS MCM0 CSS
(D)
→
(B)
0
Confirm this flag
is 1.
0 0
Unnecessary if the CPU is operating
with the internal high-speed
oscillation clock
↑
Unnecessary if
XSEL is 0
Remarks 1.
(A) to (I) in Table 5-5 correspond to (A) to (I) in Figures 5-15 and 5-16.
2.
MCM0:
Bit 0 of the main clock mode register (MCM)
OSCSELS:
Bit 4 of the clock operation mode select register (OSCCTL)
RSTS, RSTOP:
Bits 7 and 0 of the internal oscillation mode register (RCM)
CSS:
Bit 4 of the processor clock control register (PCC)