UART parity and flow control information

jacklu — Thu, 23 Apr 2015 01:01:27 GMT

Hi expert,

I want to confirm these information about UART:

1. @IMX6SL platform, UART parity only have ODD/EVEN mode, but not contain MARK and SPACE, is it right? Further more, is there any upgrade for this to support MARK & SPACE?

2. about the flow control, the spec shows that this platform only support RTS/CTS HW flow control.

what is it about DTR/DSR?

3. how to use SW flow control (XON/XOFF)?

Thank You!

BRs,

Jack

Re: UART parity and flow control information

Yuri — Fri, 24 Apr 2015 10:44:30 GMT

Jack,

Please look at my comments below.
1.

Basically PREN (Parity Enable) and PROE (Parity Odd/Even) bits of

UARTx_UCR2 registers allows to control the 9-th bit in UART frame,

but – alas – it is not possible to predefine the values of this bit as

MARK or SPACE.
Also, in RS-485 mode 9-th bit is supported : it may used to send any
data (0 /1).

2.
Yes, the UART includes hardware flow control support for request to

send (RTS_B) and clear to send (CTS_B) signals. But DTR and DSR
signals also present.

3.
From “Universal Asynchronous Receiver/Transmitter (UART) Driver”

of "i.MX_6_Linux_Reference_Manual.pdf" : the low-level UART driver has
XON/XOFF software flow control.

Have a great day,
Yuri

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topic Re: UART parity and flow control information in i.MX Processors

UART parity and flow control information

Re: UART parity and flow control information