// #################################################################################################
// # << NEORV32 - GPIO loopback >>                                                     #
// # ********************************************************************************************* #
// # BSD 3-Clause License                                                                          #
// #                                                                                               #
// # Copyright (c) 2021, Stephan Nolting. All rights reserved.                                     #
// #                                                                                               #
// # Redistribution and use in source and binary forms, with or without modification, are          #
// # permitted provided that the following conditions are met:                                     #
// #                                                                                               #
// # 1. Redistributions of source code must retain the above copyright notice, this list of        #
// #    conditions and the following disclaimer.                                                   #
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// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of     #
// #    conditions and the following disclaimer in the documentation and/or other materials        #
// #    provided with the distribution.                                                            #
// #                                                                                               #
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// #    endorse or promote products derived from this software without specific prior written      #
// #    permission.                                                                                #
// #                                                                                               #
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// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32              (c) Stephan Nolting #
// #################################################################################################


/**********************************************************************//**
 * @file gpio_loopback/main.c
 * @author Stephan Nolting
 * @brief 
 **************************************************************************/

#include <neorv32.h>


/**********************************************************************//**
 * @name User configuration
 **************************************************************************/
/**@{*/
/** UART BAUD rate */
#define BAUD_RATE 19200
/**@}*/



/**********************************************************************//**
 * Main function;
 *
 * @note This program requires the GPIO controller to be synthesized (the UART is optional).
 *
 * @return 0 if execution was successful
 **************************************************************************/
int main() {

  // init UART (primary UART = UART0; if no id number is specified the primary UART is used) at default baud rate, no parity bits, ho hw flow control
  neorv32_uart0_setup(BAUD_RATE, PARITY_NONE, FLOW_CONTROL_NONE);

  // check if GPIO unit is implemented at all
  if (neorv32_gpio_available() == 0) {
    neorv32_uart0_print("Error! No GPIO unit synthesized!\n");
    return 1; // nope, no GPIO unit synthesized
  }

  // capture all exceptions and give debug info via UART
  // this is not required, but keeps us safe
  neorv32_rte_setup();

  // say hello
  neorv32_uart0_print("GPIO loopback\n");

  while(1)
  {
    neorv32_gpio_port_set(neorv32_gpio_port_get() & 0xFF);  
  }

  return 0;
}

