LCD_RS iMX28 pin for USB BOOT MODE

[nxp_jbmbtbklg]

Hi all,

I want to boot my iMX28 board from USB and I know that I should use the boot pins LCD_DATA[5:0] to set the boot mode. My board has resistors to pulling up or down them but it has the LCD_RS pin floating. 

Is it possible booting from USB with LCD_RS pin floating? 

Thank You!

[Yuri]

Hello,

 If the OTP bit is not blown, i.MX28 will check the boot mode on LCD_D[5:0],

regardless of LCD_RS pin status.

Have a great day,
Yuri

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[nxp_jbmbtbklg]

Hello,

Sorry because right now I do not know how to check if the OTP bit is blow. My board has just arrived from manufacturing. Can I check OTP bit measuring some pin voltage of the iMX28?

Thank You!

[Yuri · Accepted solution]

Hello,

  Boot fuses in the OTP are not burned by default. As for USB recovery mode, 

it is also entered after boot errors. So, if boot mode is SD - it is enough to

leave SD slot free - and i.MX28 will enter USB recovery mode.   

Regards,

Yuri.