UART Multiplexed Pins!

[qammarabbas]

Hi,

I am interfacing UART of T1042 with MAX238 line driver IC. The UART pins on the processor are multiplexed with GPIOs and other UART Pins. How can i tell the processor to use the pin for a specific function (as USART_SIN or SOUT)? 

[r8070z · Accepted solution]

Have a great day,

On hardware reset device loads Reset Configuration Word (RCW) from an external memory. F.e. it can load RCW from NOR or NAND flash memory. Initially, on power reset few pins named as POR configuration inputs are sampled to determine the RCW source. The RCW contains 4-bit field UART_BASE which configures the functionality of the UART pins. You can find more details in chapter 4 of the T1040 reference manual. So you should prepare proper RCW[UART_BASE] which tells processor to use the pin for a specific function (as USART_SIN or SOUT)

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[qammarabbas]

Thank you!