Technical information

42
MITSUBISHI MICROCOMPUTERS
3820 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
Fig. 37 Clock generating circuit block diagram
WIT
instruction
STP instruction
Timing φ
(Internal system clock)
S
R
Q
STP instruction
S
R
Q
Main clock stop bit
S
R
Q
Timer 2
Timer 1
1/2
1/4
X IN
X OUT
X COUT
X CIN
Interrupt request
Interrupt disable flag I
Reset
1/2
Port X C switch bit
"1"
"0"
"1"
"0"
Timer 1 count
source selection
bit
"0"
"1"
Timer 2 count
source selection
bit
Low-speed mode
Middle/High-speed mode
Internal system clock selection bit
(Note 1)
Middle-speed mode
High-speed mode
or Low-speed mode
Note : When using the low-speed mode, set the port X C switch bit to "1" .
Main clock division ratio selection bit