MC9S08JM16CGTE FREESCALE [Freescale Semiconductor, Inc], MC9S08JM16CGTE Datasheet - Page 22

• Manufacturer Part Number: MC9S08JM16CGTE
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Chapter 1 Device Overview
The MCG supplies the following clock sources:
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MCGOUT — This clock source is used as the CPU, USB RAM and USB module clock, and is
divided by two to generate the peripheral bus clock (BUSCLK). Control bits in the MCG control
registers determine which of the three clock sources is connected:
— Internal reference clock
— External reference clock
— Frequency-locked loop (FLL) or phase-locked loop (PLL) output
See
MCGOUT clock.
MCGLCLK — This clock source is derived from the digitally controlled oscillator (DCO) of the
MCG. Development tools can select this internal self-clocked source to speed up BDC
communications in systems where the bus clock is slow.
MCGIRCLK — This is the internal reference clock and can be selected as the real-time counter
(RTC) clock source.
MCGIRCLK in more detail. See
information regarding the use of MCGIRCLK.
MCGERCLK — This is the external reference clock and can be selected as the clock source of
RTC and ADC module.
more detail. See
“Analog-to-Digital Converter
MCGERCLK with these modules.
MCGFFCLK — This clock source is divided by two to generate FFCLK after being synchronized
to the BUSCLK. It can be selected as clock source for the TPM modules. The frequency of the
MCGFFCLK is determined by the settings of the MCG. See the
Clock,” for details.
LPO clock— This clock is generated from an internal low power oscillator that is completely
independent of the MCG module. The LPO clock can be selected as the clock source to the RTC
or COP modules. See
Operating Properly (COP)
TPMCLK — TPMCLK is the optional external clock source for the TPM modules. The TPMCLK
must be limited to 1/4th the frequency of the BUSCLK for synchronization. See
“Timer/Pulse-Width Modulator
Chapter 12, “Multi-Purpose Clock Generator
Chapter 13, “Real-Time Counter
Chapter 12, “Multi-Purpose Clock Generator
Chapter 13, “Real-Time Counter
Section 12.4.6, “External Reference
Watchdog,” for details on using the LPO clock with these modules.
MC9S08JM16 Series Data Sheet, Rev. 2
(S08ADC12V1),” for more information regarding the use of
(S08TPMV2),” for more details.
Chapter 13, “Real-Time Counter
(S08MCGV1),” for details on configuring the
(S08RTCV1),” and
(S08RTCV1),” and
Clock,” explains the MCGERCLK in
Section 12.4.7, “Fixed Frequency
(S08MCGV1),” explains the
(S08RTCV1),” for more
Chapter 10,
Section 5.4, “Computer
Freescale Semiconductor
Chapter 16,