LPC MicrocontrollersのトピックRe: LPC4078 UART0 discarding 0xD carriage return

LPC4078 UART0 discarding 0xD carriage return

ryan1019 — Mon, 04 Jun 2018 18:39:10 GMT

I am sending in a string of text 'HelloWorld\r" with 0xD character to UART0 and outputting the same text to UART2 ,but when I probe the UART2 TX line with my logic analyzer, the data is missing the 0xD (Carriage Return) character. I've verified that on UART0 RX line that I can see the 0xD character, so why is it missing on the TX of UART2. My program is NOT using any interrupt..just simple polling and as soon as a character is detected on UART0 it is output to UART2 right away.

Re: LPC4078 UART0 discarding 0xD carriage return

Dezheng_Tang — Tue, 05 Jun 2018 22:55:18 GMT

Is the TX FIFO empty? Check the FIFO status.

Re: LPC4078 UART0 discarding 0xD carriage return

ryan1019 — Wed, 06 Jun 2018 07:43:34 GMT

I have this at the input UART

if(LPC_UART2->LSR & 0x01) { // Receive Data Ready
SData[i++]=LPC_UART2->RBR;
}

and this at the output UART

while (!(LPC_UART2->LSR & 0x20)); // TX ready
LPC_UART2->THR = ch;
return (ch);

Notice that the data is missing the CR and LF which I have sent in.

Re: LPC4078 UART0 discarding 0xD carriage return

Carlos_Mendoza — Wed, 27 Jun 2018 17:30:39 GMT

Hello Ryan,

Have you tried using the UART example that comes with the LPCOpen package to see if the same behavior is present?

LPCOpen Software for LPC40XX|NXP

Hope it helps.

Regards,

Carlos Mendoza