Question with WDT on DM8148

Hi Sir :

I work on DM8148 platform and use DVRRDK_03.00.00.00 to develop our system.

Now, I try to test watchdog function and use scope to measure RSTOUT_WD_OUT.

I refer the link below and write a test program.

http://www.deyisupport.com/question_answer/dsp_arm/davinci_digital_media_processors/f/39/t/23557.aspx

When I execute the program, the system did reboot when watchdog overflow, but RSTOUT_WD_OUT is always high.

I have checked the value of PINCNTL262 and it is 0x50001.

Could you give me some suggestion?

I was from Taiwan, so you could use Chinese.

Best regards,

Marcus

Jean Lee：

你好这位同学，我前几天也做了WDT的测试，发现Linux内核默认的驱动是热启动方式，WD_OUT不会有高低电平输出的，请将驱动换成software watchdog就可以正常启动内核了，我用的开发包是ezsdk，希望对你有帮助。

lu yuenjune：

回复 Jean Lee:

Hi Jean :

Thanks for your reply!

According your suggestion, if I turn on software watchdog in kernel, the rstout_wd_out will pull low when software watchdog overflow.

Is my understanding is correct?

Best regards,

Marcus

Jean Lee：

回复 lu yuenjune:

根据我的测试，software方式WD_OUT也没有输出，它复位的是PRCM模块，然后导致整个芯片复位的。

lu yuenjune：

回复 Jean Lee:

Hi Jean :

I appreciate your reply!

However, I need to rstout_wd_out pull low when watchdog is overflow.

I will post my question on TI E2E and if there is an answer I will let you know.

Best regards,

Marcus

Louis：

你好，

   请关注一下DATASHEET 7.3.14的描述，另外，你的BTMODE[11] PIN 是怎样接的？

lu yuenjune：

回复 Louis:

Hi Louis :

I appreciate your reply!

I use TI 8148 EVM board to test RSTOUT_WD_OUT.

I switch BTMODE[11] to low and run watchdog test program refer link below.

http://www.deyisupport.com/question_answer/dsp_arm/davinci_digital_media_processors/f/39/t/23557.aspx

When system reboot, the RSTOUT_WD_OUT is always high and it do not pull low.

Best regards,

Marcus

lu yuenjune：

回复 lu yuenjune:

Hi Jean :

You can refer the link below.

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/p/272368/954349.aspx#954349

I have saw the RSTOUT_WD_OUT pin which is pulled low over 600ns when watchdog is overflow.

I think it is hardware watchdog.

Hope this is helpful for your application.

Best regards,

Marcus

Louis：

回复 lu yuenjune:

Marcus,

  Did you doube-check the oscilloscope settings? Did you capture the RSTOUT pulse when recycle the board?

lu yuenjune：

回复 Louis:

Hi Louis :

As I mentioned above, I did see the RSTOUT_WD_OUT which was pulled low when watchdog was overflow.

So, this issue has been solved.

Best regards,

Marcus 

Jean Lee：

回复 lu yuenjune:

你好，lu yuenjune，我看了下RSTOUT脚，确实看见了电平被拉低了，DM8168与8148管脚不一样，DM8168的WD_OUT与RSTOUT是分开的，当看门狗溢出的时候RSTOUT有输出，而WD_OUT没有。

谢谢 你的回复。