7542 Group
Rev.3.03
Jul 11, 2008
Page 67 of 117
REJ03B0006-0303
Fig. 86 State transition 2
Operation clock source: On-chip oscillator (Note 2)
Operation clock source: f(XIN) (Note 1)
Notes on switch of clock
(1) In operation clock = f(XIN), the following can be selected for the CPU clock division ratio.
f(XIN)/2 (High-speed mode)
f(XIN)/8 (Middle-speed mode)
f(XIN) (Double-speed mode, only at a ceramic oscillation)
(2) In operation clock = On-chip oscillator, the following can be selected for the CPU clock division ratio.
ROSC/1 (On-chip oscillator double-speed mode)
ROSC/2 (On-chip oscillator high-speed mode)
ROSC/8 (On-chip oscillator middle-speed mode)
ROSC/128 (On-chip oscillator low-speed mode)
(3) Executing the state transition state 3 to 2 or state 3 to 3’ after stabilizing XIN oscillation.
(4) After system is released from reset, and state transition of state 2 → state 3 and state transition of state 2’ → state 3’,
ROSC/8 (On-chip oscillator middle-speed mode) is selected for CPU clock.
(5) MCU cannot be returned by On-chip oscillator and its operation is stopped since internal reset does not occur at oscillation stop detected.
Accordingly, do not execute the transition to state 2'a.
(6) STP instruction cannot be used when oscillation stop detection circuit is in active.
RESET state 2
f(XIN) oscillation: enabled
On-chip oscillator: enabled
RESET state 1
f(XIN) oscillation: enabled
On-chip oscillator: enabled
Oscillation stop detection circuit is in active. (Note 6)
Applied “L” to RESET pin
(external reset)
MISRG3 is cleared to “0”.
MISRG2=12
MISRG2=02
MISRG2=12
MISRG2=02
MISRG1=12
MISRG1=02
(MISRG3 is cleared to “0”.)
MISRG1=12
(Note 3)
MISRG1=02
(MISRG3 is cleared to “0”.)
State 3
State 2
f(XIN) oscillation: enabled
On-chip oscillator: enabled
f(XIN) oscillation: enabled
On-chip oscillator: enabled
State 3’
State 2’
f(XIN) oscillation: enabled
On-chip oscillator: enabled
State 2’a (Note 5)
Oscillation stop reset disabled
When oscillation stop is detected;
MISRG3 is set to “1”.
Internal RESET does not occur.
Prohibitive state
MUC will be locked when Ceramic
or RC oscillation is stopped.
State 3’a
Oscillation stop reset disabled
When oscillation stop is detected;
MISRG3 is set to “1”.
Internal RESET does not occur.
Oscillation stop reset enabled
When oscillation stop is detected;
MISRG3 is set to “1”.
Internal RESET occurs.
Oscillation stop reset enabled
When oscillation stop is detected;
MISRG3 is set to “1”.
Internal RESET occurs.
State 3’c
Release from internal reset
MISRG3 is set to “1”.
Oscillation status can be
confirmed by reading MISRG3.
f(XIN) oscillation: enabled
On-chip oscillator: enabled
State 3’b
State 2’b
CPUM76=102
(Note 4)
CPUM76=002
012
112
(Note 3)
CPUM76=102
CPUM76=002
012
112
CPUM76=102
(Note 4)
CPUM76=002
012
112
Reset
released
(Note 4)
Reset
released
(Note 4)
Oscillation stop is detected
(internal reset)