ez80f91 ZiLOG Semiconductor, ez80f91 Datasheet - Page 347

• Manufacturer Part Number: ez80f91
• Description: Ez80 Acclaimplus!? Connectivity Assp Ez80f91 Assp
• Manufacturer: ZiLOG Semiconductor

On-Chip Oscillators
PS027001-0707
Primary Crystal Oscillator Operation
The eZ80F91 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
If an external clock generator is used, the X
ary oscillator drives a 32 kHz crystal to generate the time-base for the Real-Time Clock.
Figure 63
external 50 MHz, 3
tions are provided in
board layout must add not more than 4 pF of stray capacitance to either the X
pins. If oscillation does not occur, try removing C1 for testing and decreasing the value of
C
2
by the estimated stray capacitance to decrease loading.
on page 340 illustrates a recommended configuration for connection with an
rd
-overtone, parallel-resonant crystal. Recommended crystal specifica-
Table 229
IN
on page 340 and
input pin also accepts a CMOS-level clock input signal.
OUT
pin must be left unconnected. The second-
Table 230
on page 341. Printed circuit
Product Specification
On-Chip Oscillators
eZ80F91 ASSP
IN
or X
OUT
339