ez80f92 ZiLOG Semiconductor, ez80f92 Datasheet - Page 227

• Manufacturer Part Number: ez80f92
• Description: Ez80acclaim Flash Microcontrollers
• Manufacturer: ZiLOG Semiconductor

On-Chip Oscillators
PS015313-0508
20 MHz Primary Crystal Oscillator Operation
The eZ80F92 device features two on-chip oscillators for use with an external crystal. The
primary oscillator generates the system clock for the internal CPU and the majority of the
on-chip peripherals. Alternatively, the X
input signal. If an external clock generator is used, the X
The secondary oscillator can drive a 32 kHz crystal to generate the time-base for the Real-
Time Clock.
Figure 51
20 MHz, fundamental-mode, parallel-resonant crystal. Recommended crystal specifica-
tions are listed in
crystal. Printed circuit board layout should add no more than 4 pF of stray capacitance to
either the X
C
1
Figure 51. Recommended Crystal Oscillator Configuration (20 MHz operation)
and C
2
displays a recommended configuration for connection with an external
to decrease loading.
IN
C = 22 pF
or X
2
Table 142
OUT
X
pins. If oscillation does not occur, reduce the values of capacitors
IN
on page 220. Resistor R
(Fundamental Mode)
On-Chip Oscillator
20 MHz Crystal
IN
2
input pin can also accept a CMOS-level clock
1
limits total power dissipation by the
OUT
pin must be left unconnected.
Product Specification
X
OUT
1
C = 22 pF
eZ80F92/eZ80F93
2
On-Chip Oscillators
219