MCF51EM128CLL Freescale Semiconductor, MCF51EM128CLL Datasheet - Page 255

• Manufacturer Part Number: MCF51EM128CLL
• Description: IC MCU 32BIT 128KB FLASH 100LQFP
• Manufacturer: Freescale Semiconductor
• Series: MCF51EMr

Specifications of MCF51EM128CLL

• Core Processor: Coldfire V1
• Core Size: 32-Bit
• Speed: 50MHz
• Connectivity: I²C, SCI, SPI
• Peripherals: LCD, LVD, PWM, WDT
• Number Of I /o: 63
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 16x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LQFP
• Processor Series: MCF51EM
• Core: ColdFire V1
• Data Bus Width: 32 bit
• Data Ram Size: 16 KB
• Interface Type: RS-232, LIN
• Maximum Clock Frequency: 50 MHz
• Number Of Timers: 3
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JLINK-CF-BDM26, EWCF
• Development Tools By Supplier: TWR-MCF51CN-KIT, TWR-SER, TWR-ELEV, TOWER
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Chapter 11
Internal Clock Source (ICS)
11.1
The Internal Clock Source (ICS) module provides several clock source choices for this device. The module
contains a frequency-locked loop (FLL) controllable by either an internal or an external reference clock.
The module can select the FLL clock, or either of the internal or external reference clocks as a source for
the MCU system clock. The selected clock source is passed through a reduced bus divider which allows a
lower output clock frequency to be derived. The ICS also controls a crystal oscillator (XOSC), which
allows an external crystal, ceramic resonator, or another external clock source to produce the external
reference clock.
The MCF51EM256 series devices are unique in that they support an independent real time clock, which
includes a dedicated oscillator in a separate power domain. The IRTC oscillator can also be used as the
reference clock into the ICS.
11.1.1
The “Clock Check & Select” feature of
the oscillator clocks for activity and control the mux which selects the external clock for the ICS. This
function is implemented external to the ICS module itself, and is specific to the MCF51EM256 series
devices.
Four registers make up this operation:
Freescale Semiconductor
Introduction
Clock Check & Select Function
MCF51EM256 Series ColdFire Integrated Microcontroller Reference Manual, Rev. 8
CCSTMRIR
CCSTMR1
CCSTMR2
CCSCTRL
Register
Table 11-1. Clock Check & Select Registers
Figure 1-3
8-bit counter incremented via IR clock timebase
8-bit counter incremented by XOSC1 timebase
8-bit counter incremented by XOSC2 timebase
Clock Check & Select Control Register
and
Figure 11-1
Function
is a very simple block used to check
11-1