f50x_lin_master.c

C8051F500开发编程：MCU全部资源应用实例

//-----------------------------------------------------------------------------
// F50x_LIN_Master.c
//-----------------------------------------------------------------------------
// Copyright 2008 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
// This program's purpose is to communicate between the A and B sides of the 
// C8051F50x target board through the Local Interconnect Network (LIN).
// 
// Pressing the P1.4_A switch will trigger the P1.3_B LED to light up. 
// Releasing the P1.4_A switch will turn off the P1.3_B LED. 
// Alternatively, pressing the P1.4_B switch will turn on the P1.3_A LED 
// while releasing the P1.4_B switch will turn off the P1.3_A LED.
//
// This example is intended to be used with the LIN_Slave example.
//
// How To Test:
//
// 1) Verify the LED and switch pin jumpers are populated 
//    (J19 for device A and J11 for device B).
//
// 2) Make sure the LIN jumpers in J17 (for A side) and J26 (for B side)
//    are connected.
//
// 3) If you wish to change the baud rate of the LIN, change the following
//    global constant: LIN_BAUD_RATE
// 
// 3) Download the code to a F50x-TB (either device A or device B) that is
//    connected as above to another device running the LIN0_Slave code.
//
// 4) Run the code.
//
// 5) If the communication passes, when a switch on a side of the target board
//    is pressed, the LED on the opposite side will light up. When said switch 
//    is released, the LED will turn off. 
//
// Target:         C8051F50x (C8051F500 TB)
// Tool chain:     Keil C51 8 / Keil EVAL C51
// Command Line:   None
//
// Revision History:
//
// Release 1.0 / 09 JUNE 2008 (ADT)
//    -Initial Revision
//
// Obs1: When the master sends a request frame, the ID sent from the master
//       is the same as the ID read by the master after a slave transmit frame,
//       even if the slave tries to edit the ID before transmitting.
//
//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------

#include <compiler_defs.h>
#include <C8051F500_defs.h>     
#include <stdio.h>

//-----------------------------------------------------------------------------
// Global Constants
//-----------------------------------------------------------------------------

SBIT (SW1, P1, 4);                     // SW1 = '0' means switch pressed
SBIT (LED, P1, 3);                     // LED = '1' means LED on

#define SYSCLK 24000000                // Clock speed in Hz

#if (SYSCLK < 8000000)                 // For the slowest baud rate
#error Minimum system clock needed to operate LIN peripheral is 8Mhz.
#endif

#define TWENTY_MS (U16)((.02/(1.0/SYSCLK)) / 12.0) // Clock cycles for 20ms

#define  LIN_BAUD_RATE 10000           // Baud Rate to run LIN peripheral
                                       // 625 < LIN_BAUD_RATE < 20000

//-----------------------------------------------------------------------------
// LIN #defines
//-----------------------------------------------------------------------------

//------ Control register ------
#define  STREQ       0x01              // LIN Master Start transmission request
#define  WUPREQ      0x02              // Wake-Up request
#define  RSTERR      0x04              // Error reset request
#define  RSTINT      0x08              // Interrupt reset request
#define  DTACK       0x10              // Slave Data ACK
#define  TXRX        0x20              // Master selection of TX or RX mode
#define  SLEEP       0x40              // Slave flag set by master to inform
                                       // the peripheral that either a sleep
                                       // mode frame or bus idle timeout
                                       // was reached
#define  STOP        0x80              // Slave flag, to be set by the
                                       // application so no processing is to be
                                       // done until next SYNCH BREAK
//------ Status Register ------
#define  DONE        0x01              // Msg. processing completed
#define  WAKEUP      0x02              // Wake-Up signal
#define  ERROR       0x04              // Error detected
#define  LININTREQ   0x08              // Interrupt request
#define  DTREQ       0x10              // ID detected
#define  ABORT       0x20              // Abort requested
#define  IDLTOUT     0x40              // Time-out detected
#define  ACTIVE      0x80              // Interface active (communicating)

#define LIN_MULTIPLIER (U8)((20000.0 / LIN_BAUD_RATE) - 1)

#if (SYSCLK >= 16000000)
 #define LIN_PRESCALAR 1
 #define LIN_DIVIDER (SYSCLK / (4 * (LIN_MULTIPLIER + 1) * LIN_BAUD_RATE))
#else
 #define LIN_PRESCALAR 0
 #define LIN_DIVIDER (SYSCLK / (2 * (LIN_MULTIPLIER + 1) * LIN_BAUD_RATE))
#endif

// Instruction Set
#define ID_SW1_SLAVE_QUERY 0x01
#define ID_LED_SLAVE       0x02        //LED on the slave side
#define ID_LED_SLAVE_OFF   0x02          
#define ID_LED_SLAVE_ON    0x03

#define LED_MASTER_OFF     0x04
#define LED_MASTER_ON      0x05 

//-----------------------------------------------------------------------------
// Global VARIABLES
//-----------------------------------------------------------------------------

UU16 Next_Interrupt_Time;              // Contains the next interrupt time that
                                       // PCA module 2 will try to match

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

void Oscillator_Init (void);           // Configure the system clock
void Port_Init (void);                 // Configure the Crossbar and GPIO
void PCA0_Init (void);                 // Configure the PCA
void LIN0_Master_Init (void);          // Configure LIN for master

INTERRUPT_PROTO (PCA0_ISR, INTERRUPT_PCA0);
INTERRUPT_PROTO (LIN0_ISR, INTERRUPT_LIN0);


//-----------------------------------------------------------------------------
// main() Routine
//-----------------------------------------------------------------------------

void main (void) 
{
   SFRPAGE = ACTIVE_PAGE;   
   
   PCA0MD &= ~0x40;                    // Disable Watchdog timer

   Oscillator_Init ();                 // Initialize the system clock
   Port_Init ();                       // Initialize crossbar and GPIO
   PCA0_Init ();                       // Initialize PCA0
   LIN0_Master_Init ();                // Initialize LIN0

   EA = 1;                             // Enable Interrupts

   LED = 0;                            // Initialize LED to be off

   while (1);                          
}

//-----------------------------------------------------------------------------
// Initialization Subroutines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// PCA0_Init
//-----------------------------------------------------------------------------
//
// Return Value:  None
// Parameters:    None
//
// Module 2 is configured as a match interrupt to be used as a periodic 
// interrupt every 20 ms.
//-----------------------------------------------------------------------------
void PCA0_Init (void)
{
   U8 SFRPAGE_save = SFRPAGE;
   SFRPAGE = ACTIVE_PAGE;

   // Configure PCA time base; overflow interrupt disabled
   PCA0CN = 0x00;                      // Stop counter; clear all flags
   PCA0MD = 0x00;                      // Use SYSCLK / 12 as time base

   PCA0CPM2 = 0x49;                    // Configure PCA0 module 2 to interrupt
                                       // periodically

   PCA0L = 0x00;                       // Set PCA0 counter to 0
   PCA0H = 0x00;

   // Initialize PCA0 module 2 to interrupt in 20 ms
   Next_Interrupt_Time.U16 = TWENTY_MS;  
   PCA0CPL2 = Next_Interrupt_Time.U8[LSB];   
   PCA0CPH2 = Next_Interrupt_Time.U8[MSB];

   EIE1 |= 0x08;                       // Enable PCA interrupts
   
   CR = 1;                             // Start PCA counter

   SFRPAGE = SFRPAGE_save;
}
//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value:  None
// Parameters:    None
//
// Configure the internal oscillator to maximum internal frequency of 24 Mhz
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
   U8 SFRPAGE_save = SFRPAGE;
   SFRPAGE = CONFIG_PAGE;

   OSCICN = 0x87;

   SFRPAGE = SFRPAGE_save;
}

//-----------------------------------------------------------------------------
// Port_Init *EDIT THIS SECTION*
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function configures the crossbar and GPIO ports.

// P0.0  -  Skipped,     Open-Drain, Digital
// P0.1  -  Skipped,     Open-Drain, Digital
// P0.2  -  Skipped,     Open-Drain, Digital
// P0.3  -  Skipped,     Open-Drain, Digital
// P0.4  -  Skipped,     Open-Drain, Digital
// P0.5  -  Skipped,     Open-Drain, Digital
// P0.6  -  Skipped,     Open-Drain, Digital
// P0.7  -  Skipped,     Open-Drain, Digital