Z8F1680SH020SG Datasheet, PDF (350/412 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F1680 Series
Product Specification
325
Caution: When using the external RC oscillator mode, the oscillator can stop oscillating if the
power supply drops below 1.6 V but remains above the Voltage Brown-Out threshold.
The oscillator resumes oscillation when the supply voltage exceeds 1.6 V.
25.4. Secondary Crystal Oscillator Operation
Figure 65 displays the recommended configuration for connection with an external funda-
mental-mode, parallel-resonant crystal operating at 32 kHz. The recommended 32 kHz
crystal specifications are provided in Table 173. Printed circuit board layout must add no
more than 4 pF of stray capacitance to either the X_IN or X_OUT pins. If oscillation does not
occur, reduce the values of capacitors C₁ and C₂ to decrease loading.
On-Chip Oscillator
XIN
C1 = 22pF
Crystal
XOUT
C2 = 22pF
Figure 65. Recommended 32 kHz Crystal Oscillator Configuration
PS025015-1212
PRELIMINARY
Crystal Oscillator