Freescale Semiconductor MC68HC08KH12 manual Control Timing, Oscillator Characteristics, 251

17.7 Control Timing

	Characteristic	Symbol	Min	Max	Unit
Internal Operating Frequency(2)		fOP	—	6	MHz
	Input Pulse Width Low(3)	tIRL	50	—	ns
RST

NOTES:

1.VDD = 4.0 to 5.5 Vdc, VSS = 0 Vdc; timing shown with respect to 20% VDD and 70% VDD, unless otherwise noted.

2.Some modules may require a minimum frequency greater than dc for proper operation; see appropriate table for this information.

3.Minimum pulse width reset is guaranteed to be recognized. It is possible for a smaller pulse width to cause a reset.

17.8 Oscillator Characteristics

Characteristic	Symbol	Min		Typ	Max	Unit
Crystal Frequency(1)	fCGMXCLK	—		6	—	MHz
External Clock	fCGMXCLK	dc		—	24	MHz
(1), (2)
Reference Frequency
Crystal Load Capacitance(3)	CL	—		—	—
Crystal Fixed Capacitance(3)	C1	—	2	⋅ CL	—
Crystal Tuning Capacitance(3)	C2	—	2	⋅ CL	—
Feedback Bias Resistor	RB	—		10	—	M Ω
Series Resistor(3), (4)	RS	—		—	—

NOTES:

1.The USB module is designed to function at fCGMXCLK = 6MHz and CGMVCLK = 48MHz. The values given here are oscillator specifications.

2.No more than 10% duty cycle deviation from 50%

3.Consult crystal vendor data sheet

4.Not Required for high frequency crystals

MC68HC(7)08KH12 — Rev. 1.1	Advance Information
Freescale Semiconductor	251