Freescale Semiconductor, Inc.
Pin Descriptions
Crystal driver and external clock input (XTAL, EXTAL)
In all cases, use caution when designing circuitry associated with the
oscillator pins. Load capacitances shown in the oscillator circuits include
all stray layout capacitances. See Figure 2-3.
25 pF
EXTAL
4•E
crystal
(a) Common crystal
connections
M68HC11
10 M¾
XTAL
25 pF
EXTAL
External oscillator
(b) External oscillator
connections
M68HC11
NC or
10–100k¾ load
XTAL
25 pF
220¾
EXTAL
EXTAL
XTAL
4•E
crystal
M68HC11
10 M¾
M68HC11
NC or
10–100k¾
load
XTAL
25 pF
(c) One crystal driving two MCUs
Note: capacitor values include all stray capacitance.
Figure 2-3. Oscillator connections
MC68HC11P2 — Rev 1.0
Technical Data
Pin Descriptions
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