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7 control timing, 8 oscillator characteristics, Control timing – Freescale Semiconductor MC68HC08KH12 User Manual

Page 251: Oscillator characteristics, 7 control timing 17.8 oscillator characteristics

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MC68HC(7)08KH12

Rev. 1.1

Advance Information

Freescale Semiconductor

251

17.7 Control Timing

17.8 Oscillator Characteristics

Characteristic

Symbol

Min

Max

Unit

Internal Operating Frequency

(2)

f

OP

6

MHz

RST Input Pulse Width Low

(3)

t

IRL

50

ns

NOTES:
1. V

DD

= 4.0 to 5.5 Vdc, V

SS

= 0 Vdc; timing shown with respect to 20% V

DD

and 70% V

DD

, 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.

Characteristic

Symbol

Min

Typ

Max

Unit

Crystal Frequency

(1)

f

CGMXCLK

6

MHz

External Clock

Reference Frequency

(1), (2)

f

CGMXCLK

dc

24

MHz

Crystal Load Capacitance

(3)

C

L

Crystal Fixed Capacitance

(3)

C

1

2

×

C

L

Crystal Tuning Capacitance

(3)

C

2

2

×

C

L

Feedback Bias Resistor

R

B

10

M

Series Resistor

(3), (4)

R

S

NOTES:
1. The USB module is designed to function at f

CGMXCLK

= 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