Use of UART_write of Ti RTOS in RS485 implementation

sandeep choudhary

Other Parts Discussed in Thread: TM4C1294KCPDT

Hi,

I have a question regarding use of TI RTOS UART drivers.

Iam using "UART_write" API of TI RTOS UART driver for sending data over a RS485 bus. The RS485 driver has echo on so whatever data i sent is echoed back to me. If I keep the recieve enable of UART during the UART_write call, I get an exception and my program terminate. If I keep the Recieve disable of UART during UART_write(), the program works fine.

Does recieving of data on UART during a UART_write() call causes issue in TI RTOS?

over 7 years ago

0 Amit Ashara over 7 years ago

TI__Guru**** 244380 points

Hello Sandeep

When the bus fault occurs, did you check the registers for trapping the Fault Type and Fault Address?

Regards
Amit

0 sandeep choudhary over 7 years ago in reply to Amit Ashara

Prodigy 150 points

Hi Amit,

I checked into the ROV to determine the cause of exception. I could see under the HWI section that there is a Undefined HWI exception. Below attached the ROV snapshot. I have also checked under BIOS>Scan For errors and it doesn't show any error over there.

0 Amit Ashara over 7 years ago in reply to sandeep choudhary

TI__Guru**** 244380 points

Hello Sandeep,

Is the correct interrupt vector being used, since the fault status registers are all 0?

Regards
Amit

0 sandeep choudhary over 7 years ago in reply to Amit Ashara

Prodigy 150 points

Hi Amit, Iam using the TI RTOS UART driver API UART_init() to initialize the UART 2 so the Interrupt vector used is correct. I can share the .cmd file and the board.c file to show you how iam initializing the UART. Iam using CAN Tivaware API's in another thread, If I stop that thread the program doesn't terminate. Iam using TM4C1294KCPDT microcontroller.

0 Amit Ashara over 7 years ago in reply to sandeep choudhary

TI__Guru**** 244380 points

Hello Sandeep

Moving the thread to TI RTOS forum as it seems to RTOS centric

Regards
Amit

0 janet over 7 years ago in reply to Amit Ashara

TI__Mastermind 22760 points

Hi Sandeep,
You should be able to receive data during a UART_write() call, but it does look like there's an issue, since disabling the RX during the UART_write() fixes the problem. Can you tell me what version of TI-RTOS you are using?
Thanks,
Janet

0 sandeep choudhary over 7 years ago in reply to janet

Prodigy 150 points

Hi Janet,

Iam using TI RTOS version 2.16.00.08. I tried replacing the TI RTOS driver API's with the Tivaware driver API's and managing the interrupt handler myself, in that case the program doesn't crash.

Processors

Processors forum

Use of UART_write of Ti RTOS in RS485 implementation