MC908GR4CDWE Freescale Semiconductor, MC908GR4CDWE Datasheet - Page 69

• Manufacturer Part Number: MC908GR4CDWE
• Description: IC MCU 4K FLASH 8MHZ 28-SOIC
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908GR4CDWE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 17
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Ram Size: 384 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 6x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Controller Family/series: HC08
• No. Of I/o's: 21
• Ram Memory Size: 384Byte
• Cpu Speed: 8MHz
• No. Of Timers: 1
• Embedded Interface Type: I2C, SCI, SPI
• Rohs Compliant: Yes
• Processor Series: HC08GR
• Core: HC08
• Data Bus Width: 8 bit
• Data Ram Size: 384 B
• Interface Type: SCI, SPI
• Maximum Clock Frequency: 8.2 MHz
• Number Of Programmable I/os: 21
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: FSICEBASE, DEMO908GZ60E, M68CBL05CE, M68EML08GPGTE
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8 bit, 6 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

Chapter 7
Clock Generator Module (CGMC)
7.1 Introduction
This section describes the clock generator module. The CGMC generates the crystal clock signal,
CGMXCLK, which operates at the frequency of the crystal. The CGMC also generates the base clock
signal, CGMOUT, which is based on either the crystal clock divided by two or the phase-locked loop (PLL)
clock, CGMVCLK, divided by two. In user mode, CGMOUT is the clock from which the SIM derives the
system clocks, including the bus clock, which is at a frequency of CGMOUT/2. In monitor mode, PTC3
determines the bus clock. The PLL is a fully functional frequency generator designed for use with crystals
or ceramic resonators. The PLL can generate an 8-MHz bus frequency using a 32-kHz crystal.
7.2 Features
Features of the CGMC include:
7.3 Functional Description
The CGMC consists of three major submodules:
Figure 7-1
Freescale Semiconductor
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Phase-locked loop with output frequency in integer multiples of an integer dividend of the crystal
reference
Low-frequency crystal operation with low-power operation and high-output frequency resolution
Programmable prescaler for power-of-two increases in frequency
Programmable hardware voltage-controlled oscillator (VCO) for low-jitter operation
Automatic bandwidth control mode for low-jitter operation
Automatic frequency lock detector
CPU interrupt on entry or exit from locked condition
Configuration register bit to allow oscillator operation during stop mode
Crystal oscillator circuit — The crystal oscillator circuit generates the constant crystal frequency
clock, CGMXCLK.
Phase-locked loop (PLL) — The PLL generates the programmable VCO frequency clock,
CGMVCLK.
Base clock selector circuit — This software-controlled circuit selects either CGMXCLK divided by
two or the VCO clock, CGMVCLK, divided by two as the base clock, CGMOUT. The SIM derives
the system clocks from either CGMOUT or CGMXCLK.
shows the structure of the CGMC.
MC68HC908GR8 • MC68HC908GR4 Data Sheet, Rev. 7
69