EM78451AP EMC [ELAN Microelectronics Corp], EM78451AP Datasheet - Page 43

• Manufacturer Part Number: EM78451AP
• Description: 8-Bit Microcontroller
• Manufacturer: EMC [ELAN Microelectronics Corp]

Product Specification (V1.2) 05.27.2004
(This specification is subject to change without further notice)
4.9.2 Crystal Oscillator/Ceramic Resonators (XTAL)
EM78451 can be driven by an external clock signal through the OSCI pin as shown in
Fig 18. In most applications, pin OSCI and pin OSCO is connected with a crystal or
ceramic resonator to generate oscillation. Fig 19 depicts such circuit. Table 10
provides the recommends values of C1 and C2. Since each resonator has its own
attribute, user should refer to its specification for appropriate values of C1 and C2. RS,
a serial resistor may be necessary for AT strip cut crystal or low frequency mode.
EM 78451
Fig. 18 Circuit for External Clock Input
EM 78451
Fig. 19 Circuit for Crystal/Resonator
OSCO
OSCI
OSCO
OSCI
XTAL
RS
X: Don’t care
NOTE
C1
C2
Ext. Clock
8-Bit Microcontroller
EM78451
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