DSP56364D Motorola Inc, DSP56364D Datasheet - Page 94

• Manufacturer Part Number: DSP56364D
• Description: 24-Bit Audio Digital Signal Processor
• Manufacturer: Motorola Inc

Design Considerations
PLL Performance Issues
One way to evaluate power consumption is to use a current per MIPS measurement methodology to
minimize specific board effects (i.e., to compensate for measured board current not caused by the DSP). A
benchmark power consumption test algorithm is listed in
current measurements, and the following equation to derive the current per MIPS value.
4.4
The following explanations should be considered as general observations on expected PLL behavior.
There is no testing that verifies these exact numbers. These observations were measured on a limited
number of parts and were not verified over the entire temperature and voltage ranges.
4.4.1
The allowed jitter on the frequency of EXTAL is 0.5%. If the rate of change of the frequency of EXTAL is
slow (i.e., it does not jump between the minimum and maximum values in one cycle) or the frequency of
the jitter is fast (i.e., it does not stay at an extreme value for a long time), then the allowed jitter can be 2%.
The phase and frequency jitter performance results are only valid if the input jitter is less than the
prescribed values.
4-4
Note:
PLL PERFORMANCE ISSUES
where :
F1 should be significantly less than F2. For example, F2 could be 66 MHz and F1
could be 33 MHz. The degree of difference between F1 and F2 determines the
amount of precision with which the current rating can be determined for an
application.
Input (EXTAL) Jitter Requirements
I MIPS
I
I
=
typF2
typF1
F2 = high frequency (any specified operating frequency)
F1 = low frequency (any specified operating frequency lower than F2)
Freescale Semiconductor, Inc.
I MHz
For More Information On This Product,
= current at F2
= current at F1
=
DSP56364 Advance Information
Go to: www.freescale.com
I typF2 I typF1
–
Appendix
F2 F1
–
A. Use the test algorithm, specific test
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