4500/720 Series 720 Family Models 4513, 4514 Group User's Manual

APPLICATION
2-64
4513/4514 Group User’s Manual
2.10 Oscillation circuit
2.10.2 Oscillation operation
System clock is supplied to CPU and peripheral device as the standard clock for the microcomputer
operation. For the 4513/4514 Group, the clock (f(XIN)), (f(XIN)/2) which is supplied from the oscillation
circuit is selected with the register MR.
Figure 2.10.2 shows the structure of the clock control circuit.
Fig. 2.10.2 Structure of clock control circuit
2.10.3 Notes on use
(1) Value of a part connected to an oscillator
Values of a capacitor and a resistor of the oscillation circuit depend on the connected oscillator and
the board. Accordingly, consult the oscillator manufacturer for values of each part connected the
oscillator.
Instruction clock
MR3
1
0
RESET
Falling detected
Ports P00, P01
Ports P02, P03
Ports P10, P11
Ports P12, P13
Multi-
plexer
K0
0,K01,K02,K03
Counter
Wait time (Note)
control circuit
Software
start signal
R
S
Q
POF instruction
XIN
XOUT
I12
0
1
P30/INT0
Key-on wake up control register
I2
2
0
1
P31/INT1
Oscillation
circuit
Division circuit
(divided by 2)
Internal clock
generation circuit
(divided by 3)
“H” level
“L” level
“H” level
Note: The wait time control circuit is used to generate the time required to stabilize the f(XIN) oscillation.
System clock