CC1312R : Uart0 flow control issue on CC1312R ,SDK3.40

robin Moon

Expert 1520 points

Part Number: CC1312R
Other Parts Discussed in Thread: SYSCONFIG

Hi ther.

My customer wants to use RS485 communication using CC1312R.

uart0 flow control is enable.

but CTS, RTS are always low while it's test.

Through sysconfig, the source was confirmed to have changed.

Is UART0 able to flow control?

Let me know how to use UART0 flow control?

Thanks.

over 5 years ago

0 Marie H over 5 years ago

TI__Guru* 81601 points

Hi Robin,

Are you using a launchpad or a custom board?

Can you post a screenshot of your UART configuration in SysConfig (or a code snippet of the generated code)?

0 IUsedToBeARealPerson (M-W) over 5 years ago in reply to Marie H

TI__Guru 58425 points

Hi Robin,

UART0 do support flow control, it should be enough for the CTS and RTS pins to be assigned in SysConfig for the driver to operate in flow control mode.

Could you in addition to Maries questions also comment on how they connect to the device and which pins they use?

0 robin Moon over 5 years ago in reply to IUsedToBeARealPerson (M-W)

Expert 1520 points

Hi and Thanks.

My customer is using a custom board.

please refer to schematic .

I attached a schematic and sysconfig.

rfEasyLinkRx.zip

0 IUsedToBeARealPerson (M-W) over 5 years ago in reply to robin Moon

TI__Guru 58425 points

Hi Robin,

I can't see any issue with the code, the flow control works as intended. CTS is an input from the other side, and the expectation is that this is asserted while it is OK to send (in other words, low means OK and high means "don't send"). RTS is an output from the device that will stay low as long as there is FIFO space to receive in and then go high when there is no room left in FIFO.

In other words, both signals being low means "we are all good" while any of these going high would indicate that there is a processing delay at either side.

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CC1312R : Uart0 flow control issue on CC1312R ,SDK3.40