C508_01 Datasheet, PDF (65/267 Pages) Infineon Technologies AG – 8-Bit CMOS Microcontroller

C508
Reset and System Clock Operation
To internal
timing circuitry
XTAL2
XTAL1
*⁾
C₁
C₂
C508
*⁾ Crystal or ceramic resonator
MCS04035
Figure 5-7 On-Chip Oscillator Circuitry
To drive the C508 with an external clock source, the external clock signal must be
applied to XTAL1, as shown in Figure 5-8. XTAL2 must be left unconnected. A pull-up
resistor is suggested (to increase the noise margin), but is optional if V_OH of the driving
gate corresponds to the V_IH3 specification of XTAL1.
C508
N.C.
V_DD
XTAL2
External
Clock
Signal
XTAL1
Figure 5-8 External Clock Source
MCS04036
User’s Manual
5-9
2001-05