• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 100 subscribers
  • Views 946 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AM3359 Frequency

Hai Nguyen73
Prodigy 20 points
Other Parts Discussed in Thread: AM3359, AM3352, AM3357, AM3356, AM3354, AM3358

Hi,

According to the AM3359 datasheet (http://www.ti.com/lit/ds/symlink/am3359.pdf), the maximum frequency of this device is 800MHz (see Table 3 on page 8).


Now, this AM3359 processor is used on the Beaglebone Black and it somehow runs at 1000MHz.  How is it possible?

Does the Beaglebone Black designer over-clock it to 1GHz?  Is this a typing error from their website (and many other wiki pages as well) or am I missing something?

Thanks,

  • 0
    TI__Guru**** 393215 points

    Hi,

    If you take a look at the BBB Schematics and BOM (http://elinux.org/Beagleboard:BeagleBoneBlack#Hardware_Files ) you will see that the part used is AM3358BZCZ100, which runs up to 1GHz.

  • 0
    Intellectual 300 points
    According the Datasheet, AM3352 300 MHz 600 MHz 800 MHz 1000 MHz AM3354 600 MHz 800 MHz 1000 MHz AM3356 300 MHz 600 MHz 800 MHz AM3357 300 MHz 600 MHz 800 MHz AM3358 600 MHz 800 MHz 1000 MHz AM3359 600 MHz 800 MHz Not suggest the chip work at over clock state for long term stable work.
  • 0 in reply to Gaven Liu
    TI__Guru**** 393215 points

    The Beaglebone Black is built with AM3358BZCZ100, not with AM3359BZCZ80. Nothing is overclocked on it. We strongly recommend customers not to try overclocking any TI processors.

  • 0 in reply to Biser Gatchev-XID
    TI__Guru*** 125430 points

    It's probably also worth quick mention that for PG2.1 silicon (i.e. current revision) that the max frequency of the part is actually FUSED in the device at test time.  The u-boot initialization code reads that register and configures the DPLL accordingly.  So if you see u-boot configuring a device for 1 GHz, that's because we tested the device to be a 1 GHz device and fused it accordingly.

  • 0 in reply to Brad Griffis
    Prodigy 20 points

    I have two Rev A of the Beaglebone Boards (right in front of me) and they both have AM3359 on them.  They only change to the AM3358 on Rev B and C.  See reference below.

    http://elinux.org/Beagleboard:BeagleBoneBlack#Revision_B

    Some picture on the web

    http://files.linuxgizmos.com/beaglebone-black-front.jpg

    http://robotic-controls.com/sites/default/files/images/beaglebone-black_0.jpg

  • 0 in reply to Hai Nguyen73
    TI__Guru*** 125430 points

    Hai Nguyen73 said:

    See reference below.

    http://elinux.org/Beagleboard:BeagleBoneBlack#Revision_B

    That reference pretty much sums it up...  Here's a quick recap of what it actually says:

    This version moves to the AM3358BZCZ100 processor as we are no longer able to get the limited production version of the AM3359AZCZ100.

    Some further explanation of what that means:

    1. AM3358A and AM3359A were the Rev 2.0 silicon devices.  These were never broadly released into production, but since the BeagleBone Black was one of the earliest users of the Rev 2.x silicon many BeagleBone Blacks shipped with Rev A (aka Rev 2.0) silicon.
    2. All BeagleBone Blacks that shipped used 1 GHz devices.
    3. The fusing of the operating speed was not consistently implemented for Rev 2.0 and so the u-boot code looks to see if it's a BeagleBone Black and if so it just hard codes it to 1 GHz, which is ok because all the BeagleBone Blacks ship with 1 GHz silicon.
    4. The original part number as indicated by the quote was AM3359AZCZ100.  That is a 1 GHz device.  You cannot order AM3359 as a 1 GHz device today, hence the reason why they moved to AM3358BZCZ100.

    Does that clarify?