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BT_CFG pins pulldowns necessary on RT1052?

Question asked by Josh Elijah on Feb 14, 2018
Latest reply on Feb 16, 2018 by Josh Elijah

I’m using the RT1052 in a system that will boot from QSPI NOR flash or a serial downloader.

 

(For reference, here are the design files i.MX RT1050 Evaluation Kit|NXP )

 

My intention is to breakout the following BT_CFG pins to a header so that I can configure the boot.

 

BT_CFG[11]

BT_CFG[8]

BT_CFG[3]

BT_CFG[2]

BT_CFG[1]

 

I want the remaining BT_CFG pins to be at logic 0.

 

My question is, do I need to pull them down externally?

 

Page 9, table 9 in the doc below suggests that I must not leave them floating

https://www.nxp.com/docs/en/user-guide/MIMXRT1050HDUG.pdf

 

But I also read that they are, by default, they are pulled low on reset (see page 75, table 70)…

https://www.nxp.com/docs/en/data-sheet/IMXRT1050CEC.pdf

 

So which one is it, can I leave these pins unconnected and rely on the internal pulldowns, or do I need to connect them to ground externally?

Thanks in advance.

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