XC228X_08 Datasheet, PDF (104/125 Pages) Infineon Technologies AG – 16/32-Bit Single-Chip Microcontroller with 32-Bit Performance

XC2287 / XC2286 / XC2285
XC2000 Family Derivatives
Electrical Parameters
4.6.3 External Clock Input Parameters
These parameters specify the external clock generation for the XC228x. The clock can
be generated in two ways:
• By connecting a crystal or ceramic resonator to pins XTAL1/XTAL2.
• By supplying an external clock signal. This clock signal can be supplied either to
pin XTAL1 (core voltage domain) or to pin CLKIN1 (IO voltage domain).
If connected to CLKIN1, the input signal must reach the defined input levels V_IL and V_IH.
In connected to XTAL1, a minimum amplitude V_AX1 (peak-to-peak voltage) is sufficient
for the operation of the on-chip oscillator.
Note: The given clock timing parameters (t₁ … t₄) are only valid for an external clock
input signal.
Table 26
External Clock Input Characteristics
(Operating Conditions apply)
Parameter
Input voltage range limits
for signal on XTAL1
Input voltage (amplitude)
on XTAL1
XTAL1 input current
Oscillator frequency
Symbol
Limit Values
Min. Typ. Max.
V_IX1 SR -1.7 + –
1.7
V_DDI
V_AX1 SR 0.3 × –
–
V_DDI
I_IL CC –
–
±20
f_OSC CC 4
–
40
4
–
16
Unit Note / Test
Condition
V
1)
V Peak-to-peak
voltage²⁾
µA 0 V < V_IN < V_DDI
MHz Clock signal
MHz Crystal or
Resonator
High time
t₁ SR 6
–
–
ns
Low time
t₂ SR 6
–
–
ns
Rise time
t₃ SR –
8
8
ns
Fall time
t₄ SR –
8
8
ns
1) Overload conditions must not occur on pin XTAL1.
2) The amplitude voltage V_AX1 refers to the offset voltage V_OFF. This offset voltage must be stable during the
operation and the resulting voltage peaks must remain within the limits defined by V_IX1.
Data Sheet
102
V2.1, 2008-08