UART Configuration

[deepanrajanbara]

Hi,

Ours is a custom board based on imx6 SBC.we are to configure the UART3(not debug UART) with 4Mbps speed .Can Anyone please tell where to set the UART speed in u-boot and Linux Kernel.

Thankyou,

Deepanraj.A

[deepanrajanbara]

Hi,

I Have tried that but am not able to check its working in minicom or teraterm.which serial terminal is possible to check .

Thankyou

[alejandrolozan1]

Hi,

I would use an scope or a logic analyzer to check the baudrate. I am not sure if those serial terminals support that baudrate.

It might be possible that even the clock source needs to be changed.  But please measure that before and let us know.

Best Regards,

Alejandro

[igorpadykov]

Hi Deepanraj

you can add debug printf to function serial_setbrg() in

uboot/drivers/serial/serial_mxc.c

to check what exact baudrate is set to UART:

void serial_setbrg (void)

{

    u32 clk = mxc_get_clock(MXC_UART_CLK);

    if (!gd->baudrate)

        gd->baudrate = CONFIG_BAUDRATE;

    __REG(UART_PHYS + UFCR) = 4 << 7; /* divide input clock by 2 */

    __REG(UART_PHYS + UBIR) = 0xf;

    __REG(UART_PHYS + UBMR) = clk / (2 * gd->baudrate);

}

Best regards

chip

[saurabh206]

Hi,

Deep

Use oscilloscope and check signals on pins.

Saurabh

[igorpadykov]

Hi Deepanraj

in Uboot you can try to set in uboot/include/configs/mx6q_sabresd.h

#define CONFIG_BAUDRATE

4000000

and check

Best regards

chip