M37517F8HP Datasheet, PDF (53/98 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

7517 Group
XCIN
XCOUT
“1” “0”
Port XC switch bit
32kHZ RC oscillation enable bit
Port XC switch bit
32kHZ RC oscillation enable bit
Data bus
32 kHZ oscillation control
registers 0, 1
Port XC switch bit
1/2
XIN
XOUT
Clock source
switch bit
Main clock division ratio
selection bit (Note 1)
Low-speed mode
XIN-XOUT oscillation
1/2
1/4 1/2
Prescaler 12
Timer 1
High-speed
on-chip
oscillation
High-speed or
middle-speed
mode
High-speed on-chip
oscillation circuit
XIN switching inhibit bit
High-speed on-chip oscillation stop bit
Main clock division ratio
selection bits (Note 1)
Middle-speed mode
High-speed or
low-speed mode
Timing φ
(Internal clock)
Main clock stop bit
QS
R
STP instruction
WIT instruction
SQ
R
QS
R
STP instruction
Reset
Interrupt disable flag l
Interrupt request
Note: Any one of high-speed mode, middle-speed mode or low-speed mode is selected by bits 7 and 6 of the CPU mode register.
When low-speed mode is selected, set port Xc switch bit (b4) to “1”.
Fig. 60 System clock generating circuit block diagram (Single-chip mode)
Rev.1.01 Aug 02, 2004 page 53 of 96