MC68HC908GP20 Datasheet, PDF (97/406 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

If the external clock (CGMXCLK) is equal to or greater than 1 MHz,
CGMXCLK can be used as the clock source for the ADC. If CGMXCLK
is less than 1 MHz, use the PLL-generated bus clock as the clock
source. As long as the internal ADC clock is at approximately 1 MHz,
correct operation can be guaranteed.
1 = Internal bus clock
0 = External clock (CGMXCLK)
A-----D-----C------i-n----p---u---t----c---l-o---c---k-----f--r--e---q---u----e---n---c---y-- _{= 1MHz}
ADIV2–ADIV0
MC68HC908GP20 — Rev 2.1
Freescale Semiconductor
Advance Information
97