max MPU freq 720MHz or 1GHz?

[graffiti]

Hi,
The webpage for the AM3352-SOM states "Texas Instruments AM3352 Cortex-A8 processor running at 1000MHz", but looking at the schematics I see that the VDD_MPU voltage is stated as 1.25V (within 4%).
According to the OPP figures for the AM335x this voltage is sufficient to run the MPU at 720MHz, but for 1GHz operation ('Nitro OPP') VDD_MPU should be 1.325V nom (min 1.272V, max 1.378V).

Any comments? Are people successfully running the AM3352-SOM at 1GHz without problems?

Thanks,
Kieran.

[graffiti]

doh, just two posts down I find this thread on the same topic:

https://www.olimex.com/forum/index.php?topic=4291.0

I guess that confirms my concern, although I'm still interested to hear if people are actually managing to run it at 1GHz?

[bruceuk]

Second that, would like to know how to run at 1Ghz

[Chester Gillon]

Any comments? Are people successfully running the AM3352-SOM at 1GHz without problems?

I had a quick test of "overclocking" the AM3352-SOM.


When set at 1GHz a SDRAM test was left running for one hour without any errors being reported.


[The test program is a bare-metal application which runs in on-chip RAM so can perform a complete test of all the SDRAM and uses a Code Composer Studio GEL script to set the CPU frequency - haven't investigated how you set the CPU frequency when the AM3352-SOM is running Linux.]


When the CPU frequency was stepped above 1GHz then:
- At 1.3GHz the SDRAM test fails on the first iteration, in that some SDRAM errors are reported and eventually the program crashes.
- At 1.25GHz the SDRAM test ran for 5 minutes without any errors reported (didn't leave running for longer in case caused any damage)


So, you can run the AM3352-SOM at 1GHz without any obvious error, but this was a test with a single board at room temperature so can't guarantee operations across device / temperature / voltage variations.