Z8F1602 ZILOG [Zilog, Inc.], Z8F1602 Datasheet - Page 183

• Manufacturer Part Number: Z8F1602
• Description: Z8 Encore Microcontrollers with Flash Memory and 10-Bit A/D Converter
• Manufacturer: ZILOG [Zilog, Inc.]

On-Chip Oscillator
20MHz Crystal Oscillator Operation
PS017610-0404
The Z8F640x family devices feature an on-chip oscillator for use with an external 1-
20MHz crystal. This oscillator generates the primary system clock for the internal eZ8
CPU and the majority of the on-chip peripherals. Alternatively, the X
accept a CMOS-level clock input signal (32kHz-20MHz). If an external clock generator is
used, the X
tain in internal clock divider. The frequency of the signal on the X
the frequency of the system clock. The Z8F640x family device on-chip oscillator does not
support external RC networks or ceramic resonators.
Figure 90 illustrates a recommended configuration for connection with an external
20MHz, fundamental-mode, parallel-resonant crystal. Recommended crystal specifica-
tions are provided in Table 99. Resistor R
Printed circuit board layout should add no more than 4pF of stray capacitance to either the
X
to decrease loading.
IN
or X
OUT
OUT
pins. If oscillation does not occur, reduce the values of capacitors C
pin must be left unconnected. The Z8F640x family device does not con-
Z8F640x/Z8F480x/Z8F320x/Z8F240x/Z8F160x
1
limits total power dissipation by the crystal.
IN
input pin determines
IN
On-Chip Oscillator
input pin can also
Z8 Encore!
1
and C
®
2
165