S908AC4MDRE FREESCALE [Freescale Semiconductor, Inc], S908AC4MDRE Datasheet - Page 244

• Manufacturer Part Number: S908AC4MDRE
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Electrical Specifications
244
RC oscillator external resistor
Crystal frequency, XTALCLK
ECFS1:ECFS0 = 00
ECFS1:ECFS0 = 01
ECFS1:ECFS0 = 10
PWU module Internal RC oscillator frequency
1. Bus frequency, f
2. Factory trimmed to provided 12.8MHz accuracy requirement (± 5%, @ 25 C and V
3. Values are based on characterization results, not tested in production.
4. Deviation values assumes trimming in target application @25 C and midpoint of voltage range, for example 5.0 V for
5. No more than 10% duty cycle deviation from 50%.
6. When external oscillator clock is greater than 1 MHz, ECFS1:ECFS0 must be 00 or 01.
7. Use fundamental mode only, do not use overtone crystals or overtone ceramic resonators.
8. Due to variations in electrical properties of external components such as, ESR and Load Capacitance, operation above
9. Do not use damping resistor when ECFS1:ECFS0 = 00 or 10.
10. Consult crystal vendor data sheet.
V
V
ECFS1:ECFS0 = 00 (V
ECFS1:ECFS0 = 00
ECFS1:ECFS0 = 01
ECFS1:ECFS0 = 10
Feedback bias resistor
Crystal load capacitance
Crystal capacitors
Crystal series damping resistor
Feedback bias resistor
Crystal load capacitance
Crystal capacitors
Feedback bias resistor
Crystal load capacitance
Crystal capacitors
DD
DD
communication. User should trim in-circuit to obtain the most accurate internal oscillator frequency for his application.
5 V ± 10% operation.
16 MHz is not guaranteed for all crystals or ceramic resonators. Operation above 16 MHz requires that a Negative
Resistance Margin (NRM) characterization and component optimization be performed by the crystal or ceramic resonator
vendor for every different type of crystal or ceramic resonator which will be used. This characterization and optimization must
be performed at the extremes of voltage and temperature which will be applied to the microcontroller in the application. The
NRM must meet or exceed 10x the maximum ESR of the crystal or ceramic resonator for acceptable performance.
f
f
f
OSCXCLK
OSCXCLK
OXCSCLK
= 5 V
= 3.3 V
= 8 MHz
= 1 MHz
= 4 MHz
OP
(10)
(10)
(10)
(9)
(9)
(9)
Characteristic
, is oscillator frequency divided by 4.
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 5
(f
(f
(f
OSCXCLK
OSCXCLK
OSCXCLK
DD
(10)
(10)
(10)
≥ 4.5 V)
(1) (7) (8)
: 8–32 MHz)
: 1–8 MHz)
: 30–100 kHz)
f
Symbol
OSCXCLK
C
C
C
f
R
INTRC
1
1
1
R
R
R
R
C
C
C
EXT
, C
, C
, C
B
S
B
B
L
L
L
2
2
2
Min
30
—
—
—
—
—
—
—
—
—
—
—
—
—
8
8
1
See
See
DD
(2 x C
(2 x C
(2 x C
= 5.0 V) for forced monitor mode
Figure 19-7
Figure 19-8
12.5
Typ
L
20
20
10
18
10
32
—
—
—
—
L
1
0
5
) –10pF
) – 5pF
L
) –10
Freescale Semiconductor
Max
100
32
16
—
—
—
—
—
—
—
—
—
—
—
—
—
8
MHz
MHz
MHz
Unit
kHz
kHz
MΩ
MΩ
MΩ
kΩ
kΩ
kΩ
pF
pF
pF
pF
pF
pF
—