Hello
We supply our borad over the DCDC_BATT Pin with 3.3V (from DCDC). We use following configuration:
When the borad powerd with 3.3V we have a reset during the barebox is starting. We can increase the FRAC_CPUFRC to 28 or HBUS_DIV to 8 and the Linux starts normally.
When we power our board with 3.8V we have no problems. The Linux starts with the fastest clock configuartion.
Vbat and VCC_Logik (confusing name I now) are connected. What is the problem?
Best regards
Peter
已解决! 转到解答。
According to footnote of Table 8 (Recommended Power Supply Operating Conditions)
of the i.MX28 Datasheet(s) :
"With external loadings (for example, one DDR2 device and SD Card/NAND Flash),
MX28 PMU was tested at BATT/DCDC_BATT > 3.30 V".
So, BATT/DCDC_BATT > 3.30 may be recommended.
Have a great day,
Yuri
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In the case, the issue may be caused because of really high (external) load.
Also, special software configuration should be applied here ; please take a look at
section 4.1.1.2 (DCDC_BATT source only: software configuration) of the app note AN4199.
http://cache.freescale.com/files/32bit/doc/app_note/AN4199.pdf
~Yuri.