nuttx-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From GitBox <...@apache.org>
Subject [GitHub] [incubator-nuttx] patacongo opened a new issue #1092: LPC17_40: UART set the buadrate jump to the Infinite loop
Date Wed, 20 May 2020 13:11:41 GMT

patacongo opened a new issue #1092:
URL: https://github.com/apache/incubator-nuttx/issues/1092


   This was Issue 173 in the old Bitbucket repository
   
   Former user
   created an issue 2019-10-09
   
   In arch/arm/src/lpc17xx_40xx/lpc17_40_serial.c, function ioctrl:
   
       lcr = getreg32(priv->uartbase + LPC17_40_UART_LCR_OFFSET);
       up_serialout(priv, LPC17_40_UART_LCR_OFFSET, (lcr | UART_LCR_DLAB));
   
       /* Set the BAUD divisor */
   
       #ifdef LPC176x
         dl = lpc17_40_uartdl(priv->baud, priv->cclkdiv);
       #else
         dl = lpc17_40_uartdl(priv->baud);
       #endif
   
        up_serialout(priv, LPC17_40_UART_DLM_OFFSET, dl >> 8);
        up_serialout(priv, LPC17_40_UART_DLL_OFFSET, dl & 0xff);
   
       /* Clear DLAB */
   
       up_serialout(priv, LPC17_40_UART_LCR_OFFSET, lcr);
   
   the DLAB can only write during the uart reg 0x7C USR bit 0 is clear。 when the uart is
busy the setting will cause the IIR[3:0] = 0111
   
   UART_16550_COMPATIBLE = NO and master has tried to write to the Line Control Register while
the DW_apb_uart is busy (USR[0] is set to 1).
   


----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
users@infra.apache.org



Mime
View raw message