
RC Oscillator Connections (No External Resistor)
MC68HC705KJ1 MC68HRC705KJ1 MC68HLC705KJ1 Data Sheet, Rev. 4.1
Freescale Semiconductor
103
A.4 RC Oscillator Connections (No External Resistor)
For maximum cost reduction, the RC oscillator mask connections shown in
Figure A-3 allow the on-chip
oscillator to be driven with no external components. This can be accomplished by programming the
oscillator internal resistor (OSCRES) bit in the mask option register to a logic 1. When programming the
OSCRES bit for the MC68HRC705KJ1, an internal resistor is selected which yields typical internal
oscillator frequencies as shown in
Figure A-4. The internal resistance for this device is different than the
resistance of the selectable internal resistor on the MC68HC705KJ1 and the MC68HRC705KJ1 devices.
Figure A-3. RC Oscillator Connections (No External Resistor)
MCU
VDD
VSS
C1
C2
OSC1
OSC2
OSC1
OSC2
R
(EXTERNAL CONNECTIONS LEFT OPEN)