AN2323 Freescale Semiconductor / Motorola, AN2323 Datasheet - Page 7

• Manufacturer Part Number: AN2323
• Description: PowerPC MPC7455 I/O Power Evaluation
• Manufacturer: Freescale Semiconductor / Motorola

Conclusion
Although I/O power is not defined in the hardware specification for the MPC7455, it is defined typically to
be less than 20% of V
frequency of 800 MHz (which is the processor frequency used for all examples at 100 MHz bus frequency).
This corresponds to a typical I/O power value of 3.4 W. The EEMBC benchmarks were used to simulate
typical applications and the I/O power measured while running these benchmarks was in the range of 200
mW, which is less than 2% of V
less than 3% of V
3 below. According to these results, I/O power as defined in the hardware specification is extremely
conservative and could more accurately be described by a smaller value.
Revision History
Table 4 lists this document’s significant changes and revisions.
MOTOROLA
Rev. No.
0.1
0.2
0
Initial release
Nontechnical reformatting
Nontechnical reformatting
Typical Power
Measured Maximum
Power
Theoretical Maximum
Power (Not Attainable)
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and maximum theoretical value is less than 7%. These results are summarized in Table
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Result
power. V
Freescale Semiconductor, Inc.
PowerPC™ MPC7455 I/O Power Evaluation
For More Information On This Product,
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power. The maximum value for power measured on the MPC7455 was
power is listed in the hardware specification at 17.0 W with a processor
Table 3. Summary of Results
Table 4. Document History
Go to: www.freescale.com
458.75 mW
204 mW
1.15 W
Power
Substantial Changes
Relation to V
Estimating Max I/O Power
< 2%
< 3%
< 7%
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Power
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