MC9S08LC36 FREESCALE [Freescale Semiconductor, Inc], MC9S08LC36 Datasheet - Page 188

• Manufacturer Part Number: MC9S08LC36
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Internal Clock Generator (S08ICGV4)
The following sections contain initialization examples for various configurations.
Important configuration information is repeated here for reference.
1
188
1
SCM — self-clocked mode (FLL bypassed
internal)
FBE — FLL bypassed external
FEI — FLL engaged internal
FEE — FLL engaged external
Ensure that
MFD Value
The IRG typically consumes 100 µA. The FLL and DCO typically consumes 0.5 to 2.5 mA, depending upon output frequency.
For minimum power consumption and minimum jitter, choose N and R to be as small as possible.
Bypassed
Engaged
FLL
FLL
000
001
010
011
f
ICGDCLK
Clock Scheme
Hexadecimal values designated by a preceding $, binary values designated
by a preceding %, and decimal values have no preceding character.
FEI
4 MHz < f
Medium power (will be less than FEE if
oscillator range = high)
Good clock accuracy (After IRG is trimmed)
Lowest system cost (no external
components required)
IRG is on. DCO is on.
SCM
This mode is mainly provided for quick and
reliable system startup.
3 MHz < f
3 MHz < f
Medium power
Poor accuracy.
IRG is off. DCO is on and open loop.
Multiplication Factor (N)
, which is equal to
Clock Reference Source = Internal
Bus
Bus
Bus
MC9S08LC60 Series Advance Information Data Sheet, Rev. 2
Table 10-11. ICGOUT Frequency Calculation Options
< 20 MHz.
< 5 MHz (default).
< 20 MHz (via filter bits).
10
Table 10-10. ICG Configuration Consideration
4
6
8
Table 10-12. MFD and RFD Decode Table
f
1
ICGOUT
(f
IRG
* R, does not exceed f
f
ext
f
ICGDCLK
/ 7)* 64 * N / R
PRELIMINARY
f
ICGOUT
f
* P * N / R
ext
NOTE
/ R
/ R
1
FEE
4 MHz < f
Medium power (will be less than FEI if
oscillator range = low)
High clock accuracy
Medium/High system cost (crystal, resonator
or external clock source required)
IRG is off. DCO is on.
FBE
f
is used.
Lowest power
Highest clock accuracy
Medium/High system cost (Crystal, resonator
or external clock source required)
IRG is off. DCO is off.
RFD
Bus
000
001
010
011
Range = 0 ; P = 64
Range = 1; P = 1
ICGDCLKmax
range ≤ 8 MHz when crystal or resonator
Clock Reference Source = External
NA
NA
64
Bus
P
< 20 MHz
.
Division Factor (R)
Typical f
immediately after reset
Typical f
Freescale Semiconductor
÷1
÷2
÷4
÷8
ICGOUT
IRG
Note
= 243 kHz
= 8 MHz