M68EVB908GB60E Freescale Semiconductor, M68EVB908GB60E Datasheet - Page 100

• Manufacturer Part Number: M68EVB908GB60E
• Description: BOARD EVAL FOR MC9S08GB60
• Manufacturer: Freescale Semiconductor
• Type: MCUr

Specifications of M68EVB908GB60E

• Contents: Module and Misc Hardware
• Processor To Be Evaluated: MC9S08GB
• Data Bus Width: 8 bit
• Interface Type: RS-232
• Silicon Manufacturer: Freescale
• Core Architecture: HCS08
• Core Sub-architecture: HCS08
• Silicon Core Number: MC9S08
• Silicon Family Name: S08GB
• Kit Contents: GB60 Evaluation Kit
• Rohs Compliant: Yes
• For Use With/related Products: MC9S08GB60
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Internal Clock Generator (ICG) Module
The module is intended to be very user friendly with many of the features occurring automatically without
user intervention. To quickly configure the module, go to
Information,” and pick an example that best suits the application needs.
7.1.1
Features of the ICG and clock distribution system:
100
•
•
•
•
•
•
•
•
•
•
•
•
•
Frequency-locked loop — A frequency-locked loop (FLL) stage takes either the internal or
external clock source and multiplies it to a higher frequency. Status bits provide information when
the circuit has achieved lock and when it falls out of lock. Additionally, this block can monitor the
external reference clock and signals whether the clock is valid or not.
Clock select block — The clock select block provides several switch options for connecting
different clock sources to the system clock tree. ICGDCLK is the multiplied clock frequency out
of the FLL, ICGERCLK is the reference clock frequency from the crystal or external clock source,
and FFE (fixed frequency enable) is a control signal used to control the system fixed frequency
clock (XCLK). ICGLCLK is the clock source for the background debug controller (BDC).
Several options for the primary clock source allow a wide range of cost, frequency, and precision
choices:
— 32 kHz–100 kHz crystal or resonator
— 1 MHz–16 MHz crystal or resonator
— External clock
— Internal reference generator
Defaults to self-clocked mode to minimize startup delays
Frequency-locked loop (FLL) generates 8 MHz to 40 MHz (for bus rates up to 20 MHz)
— Uses external or internal clock as reference frequency
Automatic lockout of non-running clock sources
Reset or interrupt on loss of clock or loss of FLL lock
Digitally-controlled oscillator (DCO) preserves previous frequency settings, allowing fast
frequency lock when recovering from stop3 mode
DCO will maintain operating frequency during a loss or removal of reference clock
Post-FLL divider selects 1 of 8 bus rate divisors (/1 through /128)
Separate self-clocked source for real-time interrupt
Trimmable internal clock source supports SCI communications without additional external
components
Automatic FLL engagement after lock is acquired
Features
MC9S08GB/GT Data Sheet, Rev. 2.3
Section 7.4, “Initialization/Application
Freescale Semiconductor