M37544 Datasheet, PDF (38/68 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

7544 Group
XIN
XOUT
Rf
Clock division ratio selection bit
Middle-, high-, low-speed mode
1/2
1/4
1/2
On-chip oscillator mode
Prescaler 1
Timer 1
Clock division
ratio selection bit
Middle-speed mode
RING
On-chip oscillator
QS
High-speed mode
Double-speed mode
1/8
On-chip oscillator mode
SQ
QS
R
STP instruction
WIT _R
R
instruction
Timing φ
(Internal clock)
STP instruction
RESET
Reset
Interrupt disable flag l
Interrupt request
Fig. 46 Block diagram of internal clock generating circuit (for ceramic/quartz-crystal resonator)
XOUT
XIN
Clock division ratio selection bit
Middle-, high-, low-speed mode
1/2
1/4
1/2
Delay
On-chip
oscillator
mode
Prescaler 1
Timer 1
Clock division
ratio selection bit
Middle-speed mode
High-speed mode
RING
On-chip oscillator
QS
Double-speed mode
1/8
On-chip oscillator mode
SQ
R
STP instruction
WIT _R
instruction
QS
R
Timing φ
(Internal clock)
RESET
STP instruction
Reset
Interrupt disable flag l
Interrupt request
Fig. 47 Block diagram of internal clock generating circuit (for RC oscillation)
Rev.1.04 2004.06.08 page 38 of 66
REJ03B0012-0104Z