main.c

一个TCP的例子

//------------------------------------------------------------------------------
// main.c
//------------------------------------------------------------------------------
// Copyright (C) 2005 Silicon Laboratories, Inc.
//
// Date: 09/21/06 17:25:55
// Target: C8051F02x
// Version: 1.01
//
// Description:
//    This Telnet echo server example shows how to use callback functions
//    to implement a Telnet (TCP) Echo Server.
//
//    This file contains the main routine, MCU initialization code, and
//    callback functions used by the TCP/IP Library.
//
// How to test:
//
//    1. Compile, Build, and Download to Target MCU + AB4.
// 
//    2. Search for the embedded system using Netfinder. If the embedded system
//       did not automatically obtain an IP address through DHCP, then manually
//       assign it an IP address. 
//
//    3. Select an embedded system in Netfinder and click Hyperterminal. 
//       You may also use any other Telnet client.
//
//    4. Open the Telnet connection (if not already opened).
//
//    5. All characters received by the echo server will be "echoed" back
//       to the terminal application.
//
// Generated by TCP/IP Configuration Wizard Version 3.2
//
#include "mn_userconst.h"                      // TCP/IP Library Constants
#include "mn_stackconst.h"                     // TCP/IP Library Constants
#include "mn_errs.h"                           // Library Error Codes
#include "mn_defs.h"                           // Library Type definitions
#include "mn_funcs.h"                          // Library Function Prototypes
#include "netfinder.h"
#include <c8051F020.h>                         // Device-specific SFR Definitions

//-----------------------------------------------------------------------------
// 16-bit SFR Definitions for 'F02x
//-----------------------------------------------------------------------------
sfr16 RCAP2    = 0xca;                         // Timer2 reload value
sfr16 TMR2     = 0xcc;                         // Timer2 counter
sfr16 ADC0     = 0xbe;                         // ADC0 data register
 
//------------------------------------------------------------------------------
// Global Constants
//------------------------------------------------------------------------------
#define SYSCLK                  22118400L      // System Clock Frequency in Hz
#define T2_OVERFLOW_RATE        32L            // Timer 2 Overflow Rate in Hz 

//------------------------------------------------------------------------------
// Function Prototypes
//------------------------------------------------------------------------------

// Initialization Routines
void PORT_Init (void);
void SYSCLK_Init (void);
void EMIF_Init(void);
int establish_network_connection();
void Timer2_Init(void);

//-----------------------------------------------------------------------------
// Main Routine
//-----------------------------------------------------------------------------
void main(void)
{
   int retval;

   // Disable watchdog timer
   WDTCN = 0xde;
   WDTCN = 0xad;

   // Initialize the MCU
   PORT_Init();
   SYSCLK_Init();
   EMIF_Init();
   Timer2_Init();

   // Reset the Netfinder Event 1 counter after a Power-On Reset or Pin Reset
   // The event1 counter counts how long the device has been powered.
   if(RSTSRC & 0x03){
      netfinder_reset_event1();
   }

   while(1)
   {
      // Initialize the TCP/IP stack.
      if (mn_init() < 0)
      {
         // If code execution enters this while(1) loop, the stack failed to initialize.
         // Verify that all boards are connected and powered properly.
         while(1);
      }

      // Connect to the network
      establish_network_connection();

      // Use DHCP to obtain an IP address.
      if (mn_dhcp_start(PTR_NULL, dhcp_default_lease_time) <= 0)
      {
         // DHCP Error
         // The DHCP server did not assign a valid IP address.
         

         // Override DHCP
         dhcp_lease.infinite_lease = 1;
         dhcp_lease.dhcp_state = DHCP_OK;

         // Specify a static IP address
         ip_src_addr[0] = 0;
         ip_src_addr[1] = 0;
         ip_src_addr[2] = 0;
         ip_src_addr[3] = 1;
      }

      // Reset Netfinder event2 counter
      // The event2 counter counts how long the device has been on a network.
      netfinder_reset_event2();

      // Start the Netfinder Service
      if( netfinder_start() < 0 )
      {
         // If code execution enters this while(1) loop, the Netfinder
         // service failed to open a UDP socket.
         //  - Verify that the current library contains UDP.
         //  - Verify that there are at least two sockets allocated.
         while(1);

      }

      // Start the Application Layer Services
      // If this routine exits, check the return value for an error code.
      retval = mn_server();

   }
}

//-----------------------------------------------------------------------------
// establish_network_connection
//-----------------------------------------------------------------------------
//
// This function calls mn_ether_init() to initialize the CP2200 and attach to
// the network.
//
// If there is a network connection, the function returns 1.
//
// In the call to mn_ether_init(), NUM_AUTONEG_ATTEMPTS is set to 0, so the
// function will not return until it successfully auto-negotiates.
//
// mn_ether_init() will not be a blocking call if NUM_AUTONEG_ATTEMPTS is set
// to a value greater than 0.
//
int establish_network_connection()
{
   int retval;

   do
   {
      // mn_ether_init() initializes the Ethernet controller.
      // AUTO_NEG indicates that the controller will auto-negotiate.
      retval = mn_ether_init(AUTO_NEG, 0, 0);

      // If there is no link, poll link_status until it sets or the
      // CP2200 resets and then call mn_ether_init() again.
      if (retval == LINK_FAIL)
      {
         while(!link_status && !ether_reset);
      }

      // If retval is less than zero and is not LINK_FAIL, there is a 
      // hardware error.
      else if (retval < 0)
      {
         // Verify that the Ethernet controller is connected and powered properly.
         // Verity that the EMIF has been configured at a speed compatible with the
         //    Ethernet controller.
         while(1);
      }

   }while(retval < 0);

   return (1);

}


//-----------------------------------------------------------------------------
// Interrupt Service Routines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// Timer2_ISR (T2_OVERFLOW_RATE Hz)
//-----------------------------------------------------------------------------
//
void Timer2_ISR (void) interrupt 5
{

   // Define static counters for real time clock (RTC).
   static unsigned int RTC_counter = 0;

   // Clear Timer 2 Overflow Flag
   TF2 = 0;

   // Check if one second has passed and update RTC.
   if(RTC_counter >= T2_OVERFLOW_RATE){

      // Clear counter and update real time clock
      RTC_counter = 0;
      netfinder_update_RTC();

   } else {
      // Increment interrupt count
      RTC_counter++;
   }

}

//-----------------------------------------------------------------------------
// Initialization Routines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Configure the Interrupts, Crossbar and GPIO ports
//
void PORT_Init (void)
{
   P1MDOUT |= 0x40;                 // Set P1.6(TB_LED) to push-pull
   P2MDOUT |= 0x08;                 // Set P2.2(AB4_LED1)
   P74OUT = 0xFF;
   P4 = 0xC0;                       // /WR, /RD, are high, RESET is low
   P5 = 0xFF;
   P6 = 0xFF;                       // P5, P6 contain the address lines
   P7 = 0xFF;                       // P7 contains the data lines

   TCON &= ~0x01;                   // Make /INT0 level triggered

   // Enable UART0, CP0, and /INT0. This puts /INT0 on P0.3.
   XBR0 = 0x84;
   XBR1 = 0x04;
   XBR2 = 0x40;

}

//-----------------------------------------------------------------------------
// EMIF_Init
//-----------------------------------------------------------------------------
//
// Configure the External Memory Interface for both on and off-chip access.
//
void EMIF_Init (void)
{

   EMI0CF = 0xFB;             // Split-mode, non-multiplexed on P0 - P3

   EMI0TC = EMIF_TIMING;      // This constant may be modified
                              // according to SYSCLK to meet the
                              // timing requirements for the CP2200

   EMI0CN = BASE_ADDRESS;     // Page of XRAM accessed by EMIF

}

//-----------------------------------------------------------------------------
// SYSCLK_Init
//-----------------------------------------------------------------------------
//
// This routine initializes the system clock.
//
void SYSCLK_Init (void)
{
   int i;                              // delay counter

   OSCXCN = 0x67;                      // start external oscillator with
                                       // 22.1184MHz crystal

   for (i=0; i < 256; i++) ;           // wait for oscillator to start

   while (!(OSCXCN & 0x80)) ;          // Wait for crystal osc. to settle

   OSCICN = 0x88;                      // select external oscillator as SYSCLK
                                       // source and enable missing clock
                                       // detector
}

//-----------------------------------------------------------------------------
// Timer2_Init
//-----------------------------------------------------------------------------
//
// This routine initializes Timer 2 to <T2_OVERFLOW_RATE> Hz.
//
void Timer2_Init(void)
{
   T2CON  = 0x00;                     // Stop Timer2; 
   CKCON  &= ~0x20;                   // Use SYSCLK/12 as timebase
 
   // Initialize Reload Value
   RCAP2 = -(SYSCLK/12/T2_OVERFLOW_RATE);
   TMR2 = RCAP2;
 
   ET2 = 1;                            // Enable Timer 2 interrupts
   TR2 = 1;                            // Start Timer 2
 
}

//-----------------------------------------------------------------------------
// ether_reset_low
//-----------------------------------------------------------------------------
//
// This routine drives the reset pin of the ethernet controller low.
//
void ether_reset_low()
{

   P4 &= ~0x20;               // Pull reset low

}

//-----------------------------------------------------------------------------
// ether_reset_high
//-----------------------------------------------------------------------------
//
// This routine places the reset pin in High-Z allowing it to be pulled up 
// using the external pull-up resistor.
//
// Additionally, this routine waits for the reset pin to read high before
// exiting.
//
void ether_reset_high (void)
{

   P4 |= 0x20;               // Allow /RST to rise
   while(!(P4 & 0x20));      // Wait for /RST to go high


}