MC68MH360EM33L Freescale Semiconductor, MC68MH360EM33L Datasheet - Page 257

• Manufacturer Part Number: MC68MH360EM33L
• Description: IC MPU QUICC ETHER 33MHZ 240FQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68MH360EM33L

• Processor Type: M683xx 32-Bit
• Speed: 33MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 240-FQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -

6.5.2 Oscillator Prescaler (Divide by 128)
In some applications, the use of a ~ 32-kHz crystal is attractive because of cost and low
power, but is not attractive due to the extra startup time required for such a slow frequency
crystal. Therefore, the SIM60 has an option for the user to provide a higher frequency crystal
(for instance, in the ~ 4-MHz range) and divide it by 128 (back down to the 32-kHz range)
before it is used by the QUICC. This results in much faster startup time than a 32-kHz crys-
tal, plus low cost (if a common 4.192-MHz frequency is chosen), with only a small impact on
power consumption during low-power modes (since the ~4-MHz frequency is immediately
MOTOROLA
MODCK1–MODCK0
MODCK1–MODCK0
EXTAL
XTAL
CLKIN
OSC.
User must select the proper MODCK configuration as well as
correct XFC capacitor value when selecting the input clock fre-
quency and desired system frequency.
For more information on MODCK see 6.5.8 Configuration Pins
(MODCK1–MODCK0). For more information on XFC see 10.8
External Capacitor for PLL.
PLL
EXTAL
DIVIDE
EXTAL
BY 128
Freescale Semiconductor, Inc.
DETECTOR
PHASE
Figure 6-5. System Clocks Schematic
For More Information On This Product,
EXTAL/128
MULTIPLICATION FACTOR (MF11–MF0)
MC68360 USER’S MANUAL
MUX
MUX
Go to: www.freescale.com
CLKIN
FILTER
LOOP
NOTE
SOFTWARE WATCHDOG AND PIT CLOCK (SPCLK)
PLL
÷ 2
STSIM BIT
(NORMALLY
OUT (2x)
MUX
MULTIPLICATION
VCO
50 MHz)
1 TO 4096
MF11–MF0
FACTOR
DIVIDE VALUES IN CDVCR
VCO
System Integration Module (SIM60)
LOW-POWER
DIVIDERS
VCO OUT
(TWICE THE
SYSTEM
FREQUENCY)
CLKO2 PIN
(NORMALLY 50 MHz)
CLKO1 PIN
SIMCLK
(NORMALLY 25 MHz)
BRGCLK
GENERAL SYSTEM
CLOCK
(NORMALLY 25 MHz)
SyncCLK
6-13