MC68HC908GT16 Datasheet, PDF (150/412 Pages) Motorola, Inc – Microcontrollers

Configuration Register (CONFIG)
Table 8-1. External Clock Option Settings
External Clock
Configuration Bits
EXTCLKEN EXTXTALEN
0
0
0
1
1
0
1
1
Pin Function
PTE4/OSC1 PTE3/OSC2
Description
PTE4
PTE3
Default setting — external oscillator disabled
PTE4
PTE3
External oscillator disabled since EXTCLKEN
not set
OSC1
PTE3
External oscillator configured for an external
clock source input (square wave) on OSC1
OSC1
OSC2
External oscillator configured for an external
crystal configuration on OSC1 and OSC2.
System will also operate with square-wave
clock source in OSC1.
OSCENINSTOP — Oscillator Enable In Stop Mode Bit
OSCENINSTOP, when set, will enable the internal clock generator
module to continue to generate clocks (either internal, ICLK, or
external, ECLK) in stop mode. See Section 7. Internal Clock
Generator (ICG) Module. This function is used to keep the timebase
running while the rest of the microcontroller stops. See Section 21.
Timebase Module (TBM). When clear, all clock generation will cease
and both ICLK and ECLK will be forced low during stop mode. The
default state for this option is clear, disabling the ICG in stop mode.
1 = Oscillator enabled to operate during stop mode
0 = Oscillator disabled during stop mode (default)
NOTE: This bit has the same functionality as the OSCSTOPENB CONFIG bit in
MC68HC908GP32 and MC68HC908GR8 parts.
COPRS — COP Rate Select Bit
COPD selects the COP timeout period. Reset clears COPRS. See
Section 9. Computer Operating Properly (COP) Module
1 = COP timeout period = 2¹³ – 2⁴ COPCLK cycles
0 = COP timeout period = 2¹⁸ – 2⁴ COPCLK cycles
Technical Data
150
MC68HC908GT16 • MC68HC908GT8 — Rev. 2
Configuration Register (CONFIG)
MOTOROLA