AT89S8252-24QC ATMEL [ATMEL Corporation], AT89S8252-24QC Datasheet - Page 17

• Manufacturer Part Number: AT89S8252-24QC
• Description: 8-bit Microcontroller with 8K Bytes Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 10. Interrupt Sources
Oscillator Characteristics
XTAL1 and XTAL2 are the input and output, respectively,
of an inverting amplifier that can be configured for use as
an on-chip oscillator, as shown in Figure 11. Either a quartz
crystal or ceramic resonator may be used. To drive the
device from an external clock source, XTAL2 should be left
unconnected while XTAL1 is driven, as shown in Figure 12.
There are no requirements on the duty cycle of the external
clock signal, since the input to the internal clocking circuitry
is through a divide-by-two flip-flop, but minimum and maxi-
mum voltage high and low time specifications must be
observed.
Figure 11. Oscillator Connections
Note:
Figure 12. External Clock Drive Configuration
Note: C1, C2 = 30 pF ± 10 pF for Crystals
= 40 pF ± 10 pF for Ceramic Resonators
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