topic Re: MX53 UART2(3) not working in i.MX Processors

MX53 UART2(3) not working

xuqing — Fri, 28 Oct 2011 03:39:06 GMT

HI everyone, Could you please let us know the issue with UART2 and UART3. IOMUX define as follows: #define MX53_PAD_EMI_D27__UART2_RXD IOMUX_PAD(0x490, 0x148, 2, 0x888, 1, MX53_UART_PAD_CTRL) #define MX53_PAD_EMI_D26__UART2_TXD IOMUX_PAD(0x48C, 0x144, 2, 0x888, 0, MX53_UART_PAD_CTRL) #define MX53_PAD_EMI_D24__UART3_TXD IOMUX_PAD(0x484, 0x13C, 2, 0x888, 0, MX53_UART_PAD_CTRL) #define MX53_PAD_EMI_D25__UART3_RXD IOMUX_PAD(0x488, 0x140, 2, 0x888, 1, MX53_UART_PAD_CTRL) tx is ok ,but rx can not receive data. Please advise us asap. We have stuck since long time.

Re: MX53 UART2(3) not working

JasonZhang1z — Wed, 02 Nov 2011 03:25:41 GMT

Maybe cased by DMA, please change arch/arm/mach-mx5/serial.h diable the DMA of these ports.

By the way, what's you version ?

Re: MX53 UART2(3) not working

JerryFan — Wed, 02 Nov 2011 04:46:21 GMT

It is a little bit strange that the UART2 and UART3 share the same daisy chain register(0x888), I thinks for UART2 the daisy chain register should be 0x880. please double check it.

Re: MX53 UART2(3) not working

LilyZhang — Wed, 02 Nov 2011 10:58:01 GMT

Please remove daisy setting for TX PINs. For example:

#define MX53_PAD_EMI_D27__UART2_RXD IOMUX_PAD(0x490, 0x148, 2, 0x888, 1, MX53_UART_PAD_CTRL)
#define MX53_PAD_EMI_D26__UART2_TXD IOMUX_PAD(0x48C, 0x144, 0, 0, 0, MX53_UART_PAD_CTRL)

#define MX53_PAD_EMI_D24__UART3_TXD IOMUX_PAD(0x484, 0x13C, 2, 0x888, 0, MX53_UART_PAD_CTRL)
#define MX53_PAD_EMI_D25__UART3_RXD IOMUX_PAD(0x488, 0x140, 0, 0, 0, MX53_UART_PAD_CTRL)

Re: MX53 UART2(3) not working

mbp — Sat, 11 Jan 2014 00:16:14 GMT

Did you get UART2 & 3 working? How?

Re: MX53 UART2(3) not working

mbp — Fri, 24 Jan 2014 21:39:54 GMT

Lily is correct. The mx51 iomux header file must be updated to correct the UART2 pin settings...