Using SCB UART with LVTTL input threshold for Rx

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RaAl_264636
Level 6
Level 6
50 sign-ins 25 sign-ins 10 solutions authored
        Hi, I need to interface a 3.3V device via UART to PSoC4, which is supplied with 5V. The 3.3V device will accept 5V input on it's Rx line. The PSoC 4 can handle the 3.3V input, but only if the corresponding port pin threshold is set to LVTTL. The problem is that the SCB UART component doesn't show the Rx/Tx pin connections, so there seems no way to configure the Rx pin. Does anyone know a way to configure the pin? Or do I have to copy the SCB component and modify it to show the pins? Regards, Ralf   
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ETRO_SSN583
Level 9
Level 9
250 likes received 100 sign-ins 5 likes given

The pin can be configed by a register write, however the controling bit

   

sets it on a port wide basis, so all other pins in that port would be forced

   

to LVTTL as well.

   

 

   

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RaAl_264636
Level 6
Level 6
50 sign-ins 25 sign-ins 10 solutions authored
        Hi Dana, I'm sorry, I missinterpreted the behaviour of the SCB component and the Creator software. I thought that it's not possible to access the pin features because they're buried inside the component. I didn't think about simply modifying the corresponding port registers *ouch* However, it's getting even better: it seems that the SCB component also creates API files for the pins used. That means that not 'port x.y' has to be modified, but simply 'uart_1_rx' - great 🙂 Regards, Ralf   
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