topic Re: Multidrop mode in MQX on 52259 in ColdFire/68K Microcontrollers and Processors

Multidrop mode in MQX on 52259

ARQuattr — Sat, 20 Nov 2010 11:44:47 GMT

I'm trying to implement 9-bit multidrop mode UART under MQX. I'm wondering what the best way to do this would be.

Can/should I modify the MCF_UARTx_UMR1, MCF_UARTx_UCR registers directly as needed ? Or should I be trying to adjust the UART init_struct (MCF52XX_UART_SERIAL_INIT_STRUCT)? Or is there some other better way? Is MQX able to handle the multidrop bit for me?

Thanks for your input,

Angelo

Re: Multidrop mode in MQX on 52259

ARQuattr — Sat, 20 Nov 2010 23:36:51 GMT

I'm able to achieve the result I'm looking for by directly accessing the MCF_... registers, and the required code is minimal so I'm satisfied with this solution, but I guess I'm just concerned that doing it like this will confilct in some way with MQX.

Re: Multidrop mode in MQX on 52259

boogy — Mon, 22 Nov 2010 22:23:23 GMT

I created my own serl_pol_mcf52xx.c found in C:\Program Files\Freescale\Freescale MQX 3.6\mqx\source\io\serial\polled

I added this statement into _mcf52xx_uart_serial_polled_ioctl

switch (cmd) {

case IO_IOCTL_SERIAL_SET_PARITY:
tmp = io_info_ptr->INIT.UMR1_VALUE & ~MCF52XX_UART_UMR1_MASK_PARITY;

  switch(*param_ptr)
  {
   case IO_SERIAL_PARITY_ODD:
    tmp |= MCF52XX_UART_UMR1_ODD_PARITY;
    break;
   case IO_SERIAL_PARITY_EVEN:
    tmp |= MCF52XX_UART_UMR1_EVEN_PARITY;
    break;
   case IO_SERIAL_PARITY_MULTI_DROP:
    tmp |= MCF52XX_UART_UMR1_MULTI_DROP;
    break;
   case IO_SERIAL_PARITY_MD_ADDRESS:
    tmp |= MCF52XX_UART_UMR1_MD_ADDRESS;
    break;
   case IO_SERIAL_PARITY_SPACE:
    tmp |= MCF52XX_UART_UMR1_LOW_PARITY;
    break;
   case IO_SERIAL_PARITY_MARK:
    tmp |= MCF52XX_UART_UMR1_HI_PARITY;
    break;
   case IO_SERIAL_PARITY_NONE:
   default:
    tmp |= MCF52XX_UART_UMR1_NO_PARITY;
    break;

}

I added to serial.h

#define IO_SERIAL_PARITY_MD_ADDRESS (7)
#define IO_SERIAL_PARITY_MULTI_DROP (8)

I don'r know why MQX hasn;'t been changed yet to do this?