MM912H634CV1AER2 Freescale Semiconductor, MM912H634CV1AER2 Datasheet - Page 268

• Manufacturer Part Number: MM912H634CV1AER2
• Description: 64KS12 LIN2xLS/HS Isense
• Manufacturer: Freescale Semiconductor
• Series: -r

Specifications of MM912H634CV1AER2

• Applications: Automotive
• Core Processor: HCS12
• Program Memory Type: FLASH (64 kB)
• Controller Series: HCS12
• Ram Size: 6K x 8
• Interface: LIN
• Number Of I /o: -
• Voltage - Supply: 5.5 V ~ 27 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP Exposed Pad
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

4.38.4.5.2
A spike in the oscillator clock can disturb the function of the modules driven by this clock.
The Adaptive Oscillator Filter includes two features:
Freescale Semiconductor
1.
2.
Filter noise (spikes) from the incoming external oscillator clock. The filter feature is illustrated in
Detect severe noise disturbance on external oscillator clock which can not be filtered and indicate the critical situation
to the software by clearing the UPOSC and LOCK status bit and setting the OSCIF and LOCKIF flag. An example for
the detection of critical noise is illustrated in
EXTAL
UPOSC
OSCCLK
PLLSEL
Core
Clock
OSCE
The Adaptive Oscillator Filter
OSCCLK
(filtered)
OSCE
OSC
FILT
EXTAL
LOCK
UPOSC
OSCCLK
(filtered)
enable external oscillator by writing OSCE bit to one.
OSCE
OSC
FILT
EXTAL
LOCK
UPOSC
Figure 100. Critical Noise Detected by the Adaptive Oscillator Filter
0
based on PLLCLK
enable external oscillator
configure the Adaptive Oscillator Filter
Figure 99. Noise Filtered by the Adaptive Oscillator Filter
> 0
crystal/resonator starts oscillating
0
enable external oscillator
configure the Adaptive Oscillator Filter
> 0
crystal/resonator starts oscillating
Figure 98. Enabling the External Oscillator
MM912_634 Advance Information, Rev. 4.0
crystal/resonator starts oscillating
select OSCCLK as Core/Bus Clock by writing PLLSEL to zero
Figure 100
UPOSC flag is set upon successful start of oscillation
based on OSCCLK
phase shift can not be filtered but detected
filtered
filtered
Figure
99.
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