UART CTS polarity

[JeHu_3414236]

I am trying to use UART on SCB2 with pin P9.3 as CTS on the BLE Pioneer Kit.  I have CTS set as active low but it will not transmit when the pin is low.  If I set it as active high, it will transmit when the pin is low.  Is this how it's supposed to work?  I use SCB5 on pins P5.0-3 that is connected to MinProg2 and it transmit with CTS active low when CTS is low.  I am connecting the PSoC 6 to a Cypress CYUSBS234 devkit UART port.  I have CTS/RTS enabled on both sides.  If I set the PSoC 6 RTS pin high or low, the CYUSBS234 transmits in both cases.  Isn't it supposed to stop transmission if RTS is high?

[AchimE_41 · Accepted solution]

Hi,

I think the problem with P9.3 is, that it is not connected to J2 by default, as the 0 Ohm resistor is loaded for Debug Trace Interface.

The second case sounds like the flow control is disabled.

Kind regards,

Achim