handshaking signals for uart

[DEVI403]

Hellow everyone,

I have code for uart transmission and reception in vhdl. Both are working fine with all requirements.

Now I need to add handshaking signal(RTS/CTS).

Can anyone Explain me how to use these signals?

1. In transmitting code which signal have to use either RTS or CTS?

I am getting confusion how to use these signals in code.
Your help would be more appreciate
Thank you

 

[std_match]

RTS (request to send) is from transmitter to receiver, and it has no direct effect on the UART core in the receiver. The software can read it, and maybe an interrupt can be generated when it changes state.

CTS (clear to send) is more important. The receiver sets it when it can receive characters. It is normally wired so the "TX register empty" bit is blocked in the transmitter when CTS is not set. That will cause a pause in the transmitter.
Some stupid UART's stopped the transmission in the middle of a character if CTS went inactive, but that is not what you want.

 

[DEVI403]

Thank you for your help.
Its very clear now.
I have included handshaking signlas in uart code.Its workinh fine.