CCS/MSP-EXP432E401Y: Does a Task waits for UART ?

Simon Maier

Intellectual 450 points

Part Number: MSP-EXP432E401Y

Tool/software: Code Composer Studio

I think about using TI-RTOS, and looked over some example code.

I've seen this UART_write command inside a Task:

UART_write(uart_rs485, TxBuffer[mailbox_msg.buf_index].protocolConverterBuf, mailbox_msg.length);

Questions:

Does this Task stops and waits here until all bytes are received?

Can other Tasks continue to run, while this UART transmission is in progress?

Do i have to use DMA?

Keep in mind that M-Bus / RS485 Communication can be very slow, down to 300 bps.

Thank you!

over 7 years ago

0 Keith Barkley over 7 years ago

Guru 42695 points

It would be a very poor RTOS if this was a blocking command. It should run in the background unless your message is larger than the buffer. Then it will block until the the bytes to be sent are smaller than the buffer size.

0 Simon Maier over 7 years ago in reply to Keith Barkley

Intellectual 450 points

What about DMA? does this command automatically uses DMA?

0 Chris Sterzik over 7 years ago in reply to Simon Maier

TI__Guru 69501 points

The UART can be configured for blocking or non-blocking mode (with callback), please refer to

http://dev.ti.com/tirex/content/simplelink_msp432e4_sdk_2_10_00_17/docs/tidrivers/doxygen/html/_u_a_r_t_8h.html

Also, the UART driver does not use the DMA peripheral. A ring-buffer is setup in SRAM.

Regards,
Chris

0 Simon Maier over 7 years ago in reply to Chris Sterzik

Intellectual 450 points

Thank you!

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CCS/MSP-EXP432E401Y: Does a Task waits for UART ?