Basic Bus Timing - Hitachi H8/300L Series Manual

6. Basic Bus Timing

The H8/300L CPU clock is generated either by the system clock generator circuit or the
subclock generator circuit. The system clock generator circuit consists of the system clock
oscillator and the system clock divider. The subclock generator circuit consists of the subclock
oscillator and the system clock divider.
Clock Generator Circuits
OSC
1 System clock
OSC oscillator
2
X
Subcock
1
oscillator
X
2
Notes: 1. The divisor n differs for each product in the series.
2. Only ø
OSC
and H8/3754 Series.
3. Only ø /8 is provided by the H8/3614 Series, H8/3714 Series, H8/3724 Series,
W
and H8/3754 Series.
ø
OSC System clock
divider (1/2)
(f )
OSC
System clock generator circuit
ø
W
Subclock divider
(1/2, 1/4, 1/8)
(f )
W
Subclock generator circuit
/2 is provided by the H8/3614 Series, H8/3714 Series, H8/3724 Series,
ø /2
OSC
System clock
divider (1/n)
ø /2
W
ø /4
W
ø /8
W
43
System
clock ø
*1
ø /2n
OSC
Subclock
ø
SUB
CPU
*2
*3