UART0 questions?

[larbi....@gmail.com]

hello

I am building my own am3358 based board

and i have a question on the uart0 in the schematic of the BBB

why do we need a SN74LVC2G241?

why dont connect directly to the header?

why a pull down resistor if uart0_rx and uart0_tx has already a internal pull up resistor?

Thanks in advance.

[Gerald Coley]

When you have the FTDI cable plugged in and you power of  the BBB, it tries to power the processor through those pins. The result is a blown processor. The 241 provide isolation. If you are careful and you never have the FTDI cable plugged in when you power off the board, you do not need it.

This is all described in the SRM.

Gerald

--
For more options, visit http://beagleboard.org/discuss
---
You received this message because you are subscribed to the Google Groups "BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/1d5905e9-9609-48fb-aca9-bab0051e3b5b%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

--

Gerald

 

ger...@beagleboard.org

http://beagleboard.org/

gco...@emprodesign.com

[William Hermans]

Sounds like "cheap insurance" to me . . .

To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAHK_S%2Bfa7ASXALZTQt-HEtzYV9U21ZuHFBC7oZZpqLwhZy5i2Q%40mail.gmail.com.