DEMO9S08EL32 Freescale Semiconductor, DEMO9S08EL32 Datasheet - Page 115

• Manufacturer Part Number: DEMO9S08EL32
• Description: BOARD DEMO FOR 9S08 EL MCU
• Manufacturer: Freescale Semiconductor
• Type: MCUr

Specifications of DEMO9S08EL32

• Contents: Evaluation Board
• Processor To Be Evaluated: MC9S08EL32
• Data Bus Width: 8 bit
• Interface Type: RS-232, USB
• Operating Supply Voltage: 12 V
• Silicon Manufacturer: Freescale
• Core Architecture: HCS08
• Core Sub-architecture: HCS08
• Silicon Core Number: MC9S08
• Silicon Family Name: S08EL
• Rohs Compliant: Yes
• For Use With/related Products: MC9S08EL32
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Chapter 8
Internal Clock Source (S08ICSV2)
8.1
The internal clock source (ICS) module provides clock source choices for the MCU. The module contains
a frequency-locked loop (FLL) as a clock source that is controllable by either an internal or an external
reference clock. The module can provide this FLL clock or either of the internal or external reference
clocks as a source for the MCU system clock. There are also signals provided to control a low power
oscillator (XOSC) module to allow the use of an external crystal/resonator as the external reference clock.
Whichever clock source is chosen, it is passed through a reduced bus divider (BDIV) which allows a lower
final output clock frequency to be derived.
The bus frequency is half of the ICSOUT frequency. After reset, the ICS is configured for FEI mode and
BDIV resets to 01 to introduce an extra divide-by-two before ICSOUT. Therefore, the bus frequency is
f
is f
8.1.1
When the internal reference is enabled in stop mode (IREFSTEN = 1), the voltage regulator must also be
enabled in stop mode by setting the LVDE and LVDSE bits in the SPMSC1 register.
Figure 8-1
Freescale Semiconductor
dco
dco_ut
/4. At POR, the TRIM and FTRIM are reset to 0x80 and 0, respectively. Therefore, the dco frequency
. For other resets, the trim settings keep the value that was present before the reset.
Introduction
shows the MC9S08EL32 block diagram with the ICS highlighted.
Module Configuration
Refer to
distribution of clock sources throughout the MCU.
Section 1.3, “System Clock
MC9S08EL32 Series and MC9S08SL16 Series Data Sheet, Rev. 3
NOTE
Distribution”,
for a detailed view of the
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