s908ey16g2vfar Freescale Semiconductor, Inc, s908ey16g2vfar Datasheet - Page 267

• Manufacturer Part Number: s908ey16g2vfar
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

20.10 External Oscillator Characteristics
Freescale Semiconductor
External clock option
External crystal options
Crystal load capacitance
Crystal fixed capacitance
Crystal tuning capacitance
EXTSLOW = 1
EXTSLOW = 0
10. Not required for high-frequency crystals
1. V
2. Setting EXTCLKEN configuration option enables OSC1 pin for external clock square-wave input.
3. No more than 10% duty cycle deviation from 50%
4. EXTSLOW configuration option configures external oscillator for a slow speed crystal and sets the clock monitor circuits
5. Some modules may require a minimum frequency greater than dc for proper operation. See appropriate table for this
6. MCU speed derates from 32 MHz at V
7. Setting EXTCLKEN and EXTXTALEN configuration options enables OSC1 and OSC2 pins for external crystal option.
8. f
9. Crystal manufacturer’s value.
With ICG clock disabled
With ICG clock enabled
External clock option (EXTSLOW = 1, RNGSEL = 0)
External clock option (EXTSLOW = 0, RNGSEL = 1)
External clock option (EXTSLOW = 0, RNGSEL = 0)
External cyrstal option (EXTSLOW = 1, RNGSEL = 0)
External crystal option (EXTSLOW = 0, RNGSEL = 1)
External crystal option (EXTSLOW = 0, RNGSEL = 0)
Feedback bias resistor
Series resistor
Feedback bias resistor
Series resistor
of the ICG module to expect an external clock frequency that is higher/lower than the internal oscillator base frequency,
f
information.
f
f
f
Bus
INTOSC.
OSCXCLK
OSCXCLK
OSCXCLK
DD
= (f
= 4.5 to 5.5 Vdc, V
EXTOSC
= 1 MHz
= 4 MHz
= 8 to 25 MHz
(9)
(9)(10)
/ 4) when external clock source is selected.
(2)(3)
Characteristic
(7)(8)
(9)
(9)
(9)
(9)
(9)
SS
= 0 Vdc, T
MC68HC908EY16A • MC68HC908EY8A Data Sheet, Rev. 1
(1)
A
DD
= –40°C to +135°C, unless otherwise noted
= 4.5 Vdc
(4)
(4)
(4)
(4)
(4)
(4)
Symbol
f
f
EXTOSC
EXTOSC
R
R
C
C
C
R
R
R
R
L
1
2
B
B
s
s
s
s
307.2
dc
Min
100
60
30
—
—
—
—
—
—
—
—
8
1
8
(5)
External Oscillator Characteristics
32.768
12.5
Typ
330
15
15
10
20
10
—
—
—
—
—
1
0
307.2
32
32
Max
100
470
32
—
—
—
—
—
—
—
—
8
8
(6)
(6)
MHz
MHz
MHz
MHz
MHz
Unit
kHz
kHz
MΩ
MΩ
kΩ
kΩ
kΩ
kΩ
pF
pF
pF
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