USB not recognized with MfgTool

[allardfrédéric]

Hello,

we are facing an issue, that when we want to load software through USB in our product, the product isn't recognized by MfgTool.

Our setup is :

Freescale processor MCIMX535DVV1C (consumer version) with Auto Start DA9053-3HC52 Dialog PMIC.

The BOOT_MODE0 and BOOT_MODE1 are tied to GND and the BOOT_CFG is configured to boot on flash.

We first plug the USB cable and then we switch ON the product.

We verified that the POR is correctly released after the 32K and 24M have started.

In this configuration, MfgTool doesn't recognize the product.

We made at least the 3 following constatations :

* When we freeze the iMX and only the iMX with a air freezer, MfgTool recognizes the product.

* We tried to boot on SD Card (by changing the BOOT_CFG). At each ON/OFF the soft is successfully loaded. Each time we do this, the system has correctly booted, and the USB is recognized. We can do then several USB plug/unplug, the USB is always recognized. But as soon as we remove the SD card, the system should boot on USB, in this case USB is not recognize.

* We did the test by forcing the serial download mode (BOOT_MODE0 and BOOT_MODE1 are pulledUp), the behavior is the same, USB is not recognized.

Has someone already seen this kind of problem ?

Thanks in advance for your feedback.

[allardfrédéric · Accepted solution]

Hi,

I have found the origin of my issue.

I have an external component with a lot of connections with iMX (data bus, GPIO, …). This external component is powered ON at the same time that the USB bloc inside the iMX. And this external component is not initialized or in reset state so its bus and GPIOs are in an undefined state.

I suppose that all these conditions cause residual voltages inside the IMX which block the USB.

I applied a workaround to delay the power ON of the external component, and it systematically works.

Thanks to All for your comments and help.

[billlau]

hi

did you connect the vbus to 5v?

i guess the signal integity should not be a problem here, if it cant run at high speed, it should run at full speed and most bad hardware can work with it.

[CarlosCasillas]

Hi,

Have you checked USB signal integrity? Do you have proper D+ and D- traces on your custom board?

Is the board not being recognized just by the MFGTool nor Windows, or it is being properly enumerated as a HID Device?

For correct operation of the i.MX53 processor, it must be properly powered-up. On application note AN4053 "i.MX51 Power-Up Sequence" you could find useful information about this.

Hope this will be useful for you.
Best regards!
/Carlos

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[allardfrédéric]

Hi,

Thanks for your feedback

We don't made the eye diagram, bur the traces are properly routed (90ohm diff) and are short.

The board is not recognized by windows.

The PMIC we use respect the power-up sequence and to be sure, we send the plot of the power sequence to Freescale support. We are waiting for their feedback. I will check the AN4053

Thanks and Best Regards, Frédéric