WHY My carrier board can't start up TX1?

您好:
我们自己打样了carrier board板卡。目前存在一种现象:有时候按下power btn按键以后无法启动TX1模块,然后长按power btn按键关机再重开才可以启动,而且这种现象在启动成功后的两到三个小时内不再复现。目前测试来看出现这种现象是概率性质的,大概重复十几次有可能复现一次,并且有的板卡一直不出现。
我们在硬件设计中,为了减小板卡面积,去掉了一些我们不用的接口电路比如sata/M.2/PCIE等等,并且去掉了power moniter电路和手动复位RESET_IN_L信号,采用12V供电。
然后在JetsonTX1_OEM_Product_DesignGuide_20170627这个文档中我找到了3.4 Power Sequencing的描述Figure 4. Power Up Sequence下的注释3:
3. During run time if any Jetson TX1 I/O rail is switched OFF or ON, the following sequences should be performed. Violating
these sequences will result in extra in-rush current during the rail transition.

  • OFF Sequence: The associated NO_IOPOWER bit in the PMC APBDEV_PMC_NO_IOPOWER_0 register must be enabled before the
    I/O Rail is powered OFF
  • ON Sequence. After an I/O Rail is powered ON, the associated NO_IOPOWER bit in the PMC APBDEV_PMC_NO_IOPOWER_0
    register needs to be cleared to the “disable” state
    我目前怀疑跟它有关,我们没有发现PMC APBDEV_PMC_NO_IOPOWER_0 register的位置,也就没有修改过NO_IOPOWER bit的参数。

以上就是我们的问题,期待您的回应

Hi mengychoo,

Welcome to Jetson & Embedded Systems developer forum.
Please create the topic and issue in English manner.
Other developers can understand your issue and to share their experience with you quickly if they ever met similar issue in design stage.
And then other users could be leverage from this issue to get benefits.

Cheers

Hi meng,

It seems has nothing with register setting as you do not switch on/off any I/O rail during run time.

It looks more like a robust issue or power source load capability issue. You’d better to probe the VDD_IN to check if any drop happen during boot up. And compare it of fail board with that of good board to find out difference.