M 6 8 E V B 9 1 2 C 3 2
0 5 / 1 5 / 0 3
11
OSC_SEL1 Option – HCS12 clock mode
OSC_SEL1 provides HCS12 oscillator configuration during device RESET configuration. The
option provides the logic value desired for the selected oscillator mode to the HCS12
PE7/XCLKS input during RESET. The OSC_SEL1 option must be configured in conjunction
with the OSC_SEL2 option for correct HCS12 operation. See the Oscillator Configuration
Table for details.
OSC_SEL1 – Crystal Oscillator Mode (Y1 circuit)
INTERNAL
EXTERNAL
OSC_SEL1 – External Clock Mode (X1 source default)
INTERNAL
EXTERNAL
OSC_SEL2 Option
OSC_SEL2 provides HCS12 oscillator or clock input selection. The option provides the input
source to the device EXTAL input pin. The OSC_SEL2 option must be configured in
conjunction with the OSC_SEL1 option for correct HCS12 operation. See the Oscillator
Configuration Table for details.
OSC_SEL2 – Crystal Oscillator Mode (Y1 circuit)
CRYSTAL
EXT_CLOCK
OSC_SEL2 – External Clock Mode (X1 source)
CRYSTAL
EXT_CLOCK
Oscillator Configuration Table
OSCILLATOR SOURCE
OSC_SEL1 Setting
OSC_SEL2 Setting
X1 clock
EXTERNAL
EXT_CLOCK
Y1 crystal
INTERNAL
CRYSTAL
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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