topic Re: IMX6 : swap debug uart pin in i.MX Processors

IMX6 : swap debug uart pin

Cécile — Sun, 01 Jan 2023 15:06:36 GMT

Hello,

I'm trying to invert the Tx and Rx pin of the UART1 debug bus, on the sabresd board.
I try to change to DTE mode like this :

mx6sabresd.c

static iomux_v3_cfg_t const uart1_pads[] = { IOMUX_PADS(PAD_CSI0_DAT11__UART1_TX_DATA | MUX_PAD_CTRL(UART_PAD_CTRL)), IOMUX_PADS(PAD_CSI0_DAT10__UART1_RX_DATA | MUX_PAD_CTRL(UART_PAD_CTRL)), };

imxqdl-sabresd.dtsi

pinctrl_uart1: uart1grp { fsl,pins = < MX6QDL_PAD_CSI0_DAT11__UART1_TX_DATA 0x1b0b1 MX6QDL_PAD_CSI0_DAT10__UART1_RX_DATA 0x1b0b1 >; }; [...] &uart1 { pinctrl-names = "default"; fsl,dte-mode; pinctrl-0 = <&pinctrl_uart1>; status = "okay"; };

But it doesn't work...
What am I missing?

Thank you for your help !

Cécile

Re: IMX6 : swap debug uart pin

Dhruvit — Thu, 12 Jan 2023 06:12:13 GMT

hello @Cécile ,

I hope You are doing well.

->The chip-level IOMUX modifies the direction and routing of the UART signals based on whether the UART is operating in DCE mode (UARTn_UFCR[DCEDTE]=0) or DTE mode (UARTn_UFCR[DCEDTE]=1). So one should always set DTE Mode.(UARTn_UFCR[DCEDTE] = 1)

->For DTE Mode One has to configure the pin setting of UART1_RX/TX_DATA & UART1_CTS/RTS_B as shown in the attachments. I've attached the attachments for the reference , please find the same.

Thanks & Regards

Dhruvit Vasavada

Re: IMX6 : swap debug uart pin

Dhruvit — Thu, 12 Jan 2023 06:13:43 GMT

Hi @Cécile

Please find the attachments.

Thanks & Regards

Dhruvit Vasavada