4501_M Datasheet, PDF (56/212 Pages) Renesas Technology Corp – 4-BIT CISC SINGLE-CHIP MICROCOMPUTER 4500 SERIES

4501 Group
HARDWARE
FUNCTION BLOCK OPERATIONS
D
RAM back-up
(Voltage drop detection
circuit is operating.)
POF instruction execution
Key-on wakeup
(Stabilizing time b )
B
Operating
Operation source clock:
ceramic resonator
On-chip oscillator: stop
RC oscillation circuit: stop
POF2 instruction execution
Key-on wakeup
(Stabilizing time b )
POF instruction execution
Voltage drop
(Stabilizing
detected
Reset ^{time a )}
CMCK instruction
execution (Note 3)
A
Operating
POF2 instruction execution
Operation source clock:
on-chip oscillator clock
Key-on wakeup
(Stabilizing time a )
POF instruction execution
Ceramic resonator:
operating (Note 2)
RC oscillation circuit: stop
Key-on wakeup
(Stabilizing time a )
CRCK instruction
execution (Note 3)
C
Operating
POF2 instruction execution
Operation source clock:
RC oscillation
Operation source clock: stop
Key-on wakeup
(Stabilizing time c )
On-chip oscillator: stop
Ceramic resonator: stop
Key-on wakeup
(Stabilizing time c )
E
RAM back-up
(All functions of
microcomputer stop)
Operation source clock: stop
Stabilizing time a : Microcomputer starts its operation after counting the on-chip oscillator clock 5359 times by hardware.
Stabilizing time b : Microcomputer starts its operation after counting the f(XIN) 5359 times by hardware.
Stabilizing time c : Microcomputer starts its operation after counting the f(XIN) 165 times by hardware.
Notes 1: Continuous execution of the EPOF instruction and the POF or POF2 instruction is required to go into
the RAM back-up state.
2: Through the ceramic resonator is operating, the on-chip oscillator clock is selected as the operation source clock.
3: The oscillator clock corresponding to each instruction is selected as the operation source clock,
and the on-chip oscillator is stopped.
Fig. 39 State transition
POF or
EPOF instruction + _POF2
instruction
Reset input
Power down flag P
SQ
R
POF or
q Set source ^{• • • • • • •} EPOF instruction + POF2
instruction
q Clear source• • • • • • Reset input
Program start
P = “1”
Yes
?
No
Cold start
Warm start
Fig. 40 Set source and clear source of the P flag
Fig. 41 Start condition identified example using the SNZP in-
struction
Rev.2.01 Feb 07, 2005
REJ09B0192-0201
1-44