455A Datasheet, PDF (58/148 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

455A Group
Fig 56. State transition
POF or
EPOF instruction + _POF2
instruction
Reset input
Power down flag P
S QP
R
POF or
Set source ^{• • • • • • •} EPOF instruction + POF2
instruction
Clear source• • • • • • System reset
Fig 57. Set source and clear source of the P flag
Program start
SNZP
instruction
P = “1”
?
No
Cold start
Yes
Yes
Warm start
T3F = “1”
?
No
SNZT3
instruction
Return from
timer 3 underflow
Return from
external wakeup signal
Fig 58. Start condition identified example using the
SNZP instruction
Rev.1.01 Feb 15, 2008 Page 58 of 146
REJ03B0224-0101