Z8S180 Zilog., Z8S180 Datasheet - Page 184

• Manufacturer Part Number: Z8S180
• Description: ENHANCED Z180 MICROPROCESSOR
• Manufacturer: Zilog.

Co
Rs
CL1, CL2
Item
Frequency
Note:
Table 25. Z8X180 Operating Frequencies
If an external clock input is used instead of a crystal, the waveform (twice
the clock rate) must exhibit a 50%
Figure 70.
Figure 71 illustrates the Z8X180 clock generator circuit while Figures 72
and 72 specify circuit board design rules.
Clock
The minimum clock input High voltage level is V
external clock input is connected to the EXTAL pin, while the
XTAL pin is left open. Figure 70 depicts the external clock
interface.
EXTAL
XTAL
10 to 22 pF
External Clock Interface
4MHz
3
2
60
7 pF
Open
10%
4MHz
10 to 22 pF
External Clock Input
10% duty cycle.
f
60
7 pF
12MHz
10%
M PU Us e r M anual
UM005001-ZMP0400
12MHz
Z 8018x Fam il y
10 to 22 pF
CC
–0.6V. The
60
7 pF
f
33MHz
10%
169