MC908JL8CDWE Datasheet, PDF(188/212 Page) Freescale Semiconductor, Inc

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MC908JL8CDWE Datasheet, PDF (188/212 Pages) Freescale Semiconductor, Inc – Microcontrollers

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Electrical Specifications

17.6 5V Control Timing

Table 17-5. Control Timing (5V)

Characteristic(1)

Symbol

Min

Max

Unit

Internal operating frequency

RST input pulse width low(2)

TIM2 external clock input

IRQ interrupt pulse width low (edge-triggered)(3)

IRQ interrupt pulse period(3)

fOP

MHz

tRL

750

fT2CLK

MHz

tILIH

100

tILIL

Note(4)

tCYC

1. VDD = 4.5 to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH; timing shown with respect to 20% VDD and 70% VSS, unless otherwise

noted.

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

3. Values are based on characterization results, not tested in production.

4. The minimum period is the number of cycles it takes to execute the interrupt service routine plus 1 tCYC.

tRL

RST

tILIL

tILIH

IRQ

Figure 17-1. RST and IRQ Timing

17.7 5V Oscillator Characteristics

Table 17-6. Oscillator Specifications (5V)

Characteristic

Internal oscillator clock frequency

Symbol

Min

fICLK

Typ

50 k(1)

Max

Unit

External reference clock to OSC1 (2)

fOSC

32 M

Crystal reference frequency (3)

Crystal load capacitance (4)

Crystal fixed capacitance (3)

Crystal tuning capacitance (3)

Feedback bias resistor

Series resistor (3), (5)

fXTALCLK

32 M

2 Ã CL

10 Mâ¦

External RC clock frequency

RC oscillator external R

RC oscillator external C

fRCCLK

12 M

REXT

See Figure 17-2

â¦

CEXT

1. Typical value reflect average measurements at midpoint of voltage range, 25 Â°C only. See Figure 17-5 for plot.

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

3. Fundamental mode crystals only.

4. Consult crystal vendor data sheet.

5. Not required for high frequency crystals.

MC68HC908JL8/JK8 â¢ MC68HC08JL8/JK8 â¢ MC68HC908KL8 Data Sheet, Rev. 3.1

188

Freescale Semiconductor

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