Code not executing on TM4C1294NCPDT

Adithya Kiran1

Other Parts Discussed in Thread: TM4C1294NCPDT

I am using Tiva TM4C1294NCPDT on a custom board. The microcontroller can run code only when there is a pullup on the UART5 RX pin. This might be most likely a biasing issue but has anyone encountered something similar before or can you suggest any tests I can run to find out what is the issue. Without the pullup the code does not execute. Please suggest some steps to verify if my MCU power is alright. I realised that the pullup on the UART pin makes the code run only because I was using that UART for sending debug trace messages to my PC and the code was executing only when I connected the UART-USB converter.

over 10 years ago

0 Amit Ashara over 10 years ago

TI__Guru**** 244400 points

Hello Adithya,

The Idle State of the UART bus is High. When the UART RX is held low, the UART controller would believe it to be a valid transaction and then wait for the Completion causing it not to work.

Regards
Amit

0 Adithya Kiran1 over 10 years ago in reply to Amit Ashara

Prodigy 120 points

The UART Rx is pulled high. Anyways for the time being I disabled the UART interrupt in the NVIC and it seems to have temporarily solved my issue

0 Amit Ashara over 10 years ago in reply to Adithya Kiran1

TI__Guru**** 244400 points

Hello Adithya,

Remember that you are working around the issue and not necessarily solving the issue of the UART RX line being low, which is coming from outside of the device

Regards
Amit

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Code not executing on TM4C1294NCPDT