I am working on a project with iMX6 solo processor. all the power supplys are OK, I connected the board with JTAG and ULINK Pro, and I can run instructions. Now I want to port the linux operation system into my board using serial download and test DDR, all require USB OTG to run. I have no way to know whether the USB is working or no if I don't write the USB driver. My question are: Is there driver code in the ROM booting code? How do I know whether my USB is working or not? Is there any program to test the USB witout using the operating system?
when I plug my USB OTG to a PC, I can hear the USB identification sound, but the device manager show nothing about the USB OTG, I tried to find new device with device manager, it shows unknown device, and can not communicate with the USB OTG.
I checked the Dn and Dp signal under the condition that the plag A was plugged in the host, but the host was not turned on so VBUS had no power, it seems the pull up and pull down resistors were working. The only suscipious is the ID pin, I use T4 (GPIO_1) as the ID pin, but the reference use w23 (Enet_Rx_ER) as the ID pin, does this an issue? if so, have a solution?
included are the plots for Dp and Dn with plud A plugged in and not plugged in.
It is the same for win 10, I guess the USB does not work. below is the captured waveform on D+ and D-, green one is for D+,blue one is for D-. I am new on USB, which period is it in the process of attachment of the USB?
I checked other USB device, it seems that the sequence above is a standard Windows sequence, other device has response, my USB has no responce, included is the circuit, any thing wrong? Included are USB circuit and the waveforms observed on L23 pin4、 pin 2 and and pin 3, purple is observed on pin 4,blue is from pin 3, green one is from pin 2. It seems the signal is OK.
1. USB OTG On board should work in device mode
USB_OTG_ID pin should be pulled up to HIGH via 10k resistor.
it means that if USB_OTG_ID is HIGH level, USB OTG will work in device mode.
2. Connecting it to PC USB
If connecting board to PC USB, windows 10 will driver it to be HID Compliance device, don't need to install driver for windows 10.
So you should check if you can find "HID Compliance device".
3. Programming images into eMMC/SD on board
If HID Compliance device is OK, you can use uuu tool to program images into eMMC/SD card on board.
Have a nice day!