This article will discuss the different tradeoffs of running the processor at different frequencies.
Acronyms:
1. POH - Power on Hours
2. OPP - Operating Performance Point
3. TRM - Technical Reference Manual
Considerations:
When considering the OPP at which you will run the SOM processor, first consult the Technical Reference Manual and data sheet for the processor; this note will only briefly cover the topic.
For a given CPU junction temperature a processor's POH will be inversely related to the OPP that the processor runs at. In some cases it is possible to cut the POH of the processor in half. If you are designing a device that is expected to be running in the field for several years, then you will need to balance POH with OPP so that your device will continue to operate as expected.
Processor Specific Documentation Highlights:
DM3730:
* Data sheet - Table 4-20 Processor Clocks
* Data sheet - Table 3-3 Reliability Data
OMAP-L138:
* Data sheet - Table 4-1 Recommended Power-On Hours
Modifying OPP in Logic PD BSPs:
Documentation on thermal and power management for several BSPs, developed by Logic PD, are available on the downloads page[1]. If you are using a BSP developed by logic PD and cannot find documentation on how to modify the OPP, contact us to let us know about your needs.
Links:
1.
http://support.logicpd.com/