MC9S08GB60ACFUE Freescale, MC9S08GB60ACFUE Datasheet - Page 118

• Manufacturer Part Number: MC9S08GB60ACFUE
• Manufacturer: Freescale

Specifications of MC9S08GB60ACFUE

• Cpu Family: HCS08
• Device Core Size: 8b
• Frequency (max): 40MHz
• Interface Type: I2C/SCI/SPI
• Total Internal Ram Size: 4KB
• # I/os (max): 56
• Number Of Timers - General Purpose: 8
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 1.8/2.08V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 64
• Package Type: LQFP
• Program Memory Type: Flash
• Program Memory Size: 60KB
• Lead Free Status / RoHS Status: Compliant

Internal Clock Generator (S08ICGV2)
7.4.2
In this example, the FLL will be used (in FEE mode) to multiply the external 32 kHz oscillator up to
8.38 MHz to achieve 4.19 MHz bus frequency.
After the MCU is released from reset, the ICG is in self-clocked mode (SCM) and supplies approximately
8 MHz on ICGOUT, which corresponds to a 4 MHz bus frequency (f
The clock scheme will be FLL engaged, external (FEE). So
Solving for N / R gives:
The values needed in each register to set up the desired operation are:
ICGC1 = $38 (%00111000)
ICGC2 = $00 (%00000000)
ICGS1 = $xx
ICGS2 = $xx
ICGFLTLU/L = $xx
ICGTRM = $xx
118
Bit 7
Bit 6
Bit 5
Bits 4:3 CLKS
Bit 2
Bit 1
Bit 0
Bit 7
Bits 6:4 MFD
Bit 3
Bits 2:0 RFD
This is read only except for clearing interrupt flag
This is read only; should read DCOS = 1 before performing any time critical tasks
Only needed in self-clocked mode; FLT will be adjusted by loop to give 8.38 MHz DCO clock
Bits 15:12 unused
Bits 11:0 FLT
Bits 7:0
Example #1: External Crystal = 32 kHz, Bus Frequency = 4.19 MHz
HGO
RANGE
REFS
OSCSTEN 0
LOCD
LOLRE
LOCRE
TRIM
N / R = 8.38 MHz /(32 kHz * 64) = 4 ; we can choose N = 4 and R =1
0
0
1
11
0
0
0
000 Sets the MFD multiplication factor to 4
0
000 Sets the RFD division factor to ÷1
0000
No need for user initialization
Only need to write when trimming internal oscillator; not used when external
crystal is clock source
f
ICGOUT
Configures oscillator for low-power operation
Configures oscillator for low-frequency range; FLL prescale factor is 64
Oscillator using crystal or resonator is requested
FLL engaged, external reference clock mode
Oscillator disabled in stop modes
Loss-of-clock detection enabled
Unimplemented or reserved, always reads zero
Generates an interrupt request on loss of lock
Generates an interrupt request on loss of clock
= f
ext
MC9S08GB60A Data Sheet, Rev. 2
* P * N / R ; P = 64, f
ext
= 32 kHz
Bus
).
Freescale Semiconductor
Eqn. 7-1
Eqn. 7-2