Rainbow Electronics AT90S8515 - Manual (Page 6)

6
AT90S8515
0841G–09/01
Crystal Oscillator XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier that can
be configured for use as an on-chip oscillator, as shown in Figure 2. Either a quartz
crystal or a 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 3.
Figure 2. Oscillator Connections
Note: When using the MCU oscillator as a clock for an external device, an HC buffer should be
connected as indicated in the figure.
Figure 3. External Clock Drive Configuration
XTAL2
XTAL1
GND
C2
C1
MAX 1 HC BUFFER
HC