µ
PD754144, 754244
20
Data Sheet U10040EJ2V1DS
Figure 7-1.
µ
PD754144 (RC Oscillation) Clock Generator Block Diagram
Note
Instruction execution
Remarks 1.
f
cc
: System clock frequency
2.
Φ
= CPU clock
3.
PCC: Processor Clock Control Register
4.
One clock cycle (t
CY
) of the CPU clock is equal to one machine cycle of the instruction.
CL1
CL2
System
clock
oscillator
Oscillation stops
1/1~1/4096
1/2 1/4 1/16
f
cc
Divider
1/4
Φ
HALT F/F
S
R
Q
S
R
Q
STOP F/F
PCC0
PCC1
PCC2
PCC3
PCC2,
PCC3
clear
HALT
Note
STOP
Note
Wait release signal from BT
Reset signal
Standby release signal from
interrupt control circuit
PCC
4
· Basic interval timer (BT)
· Timer counter
· INT0 noise eliminator
· CPU
· INT0 noise
eliminator
Divider
Selector
Internal bus
*