executive.c

ov7620是采用cmos传感器技术的摄像头

/***********************************************************
    Module Name: Executive.c
    Module Date: 04/12/2004
    Module Auth: John Orlando 
    Copyright (c) 2004 John Orlando  All Rights Reserved 

    Description: This file is responsible for implementing a
    minimalist event dispatcher.  It keeps track of an event
    fifo that waits for new events to come in, and dispatches
    them to any entities that care about them.
    ***********************************************************/

/*	Includes */
#include <stdlib.h>
#include "CommonDefs.h"
#include "Executive.h"
#include "FrameMgr.h"
#include "CamInterface.h"
#include "UIMgr.h"
#include "UartInterface.h"
#include "CamConfig.h"
#include "Utility.h"

/*  Local Variables */
unsigned char Exec_eventFifo[EXEC_EVENT_FIFO_SIZE];
unsigned char Exec_eventFifoHead=0;
unsigned char Exec_eventFifoTail=0;

/*  Local Function Definitions */
static unsigned char Exec_readEventFifo(void);

/* 	Local Structures and Typedefs */

/*  Extern Variables */
/* This bitmask holds events that need to be processed as fast as possible */
unsigned char fastEventBitmask = 0x00;

/*  Definitions */
#define IS_DATA_IN_EVENT_FIFO() (!(Exec_eventFifoHead == Exec_eventFifoTail))
/***********************************************************
    Function Name: Exec_run
    Function Description: This function is responsible for
    running the main control loop.  The control loop is
    based on checking both the fast-event bitmask (for high
    priority events) and the event FIFO to determine if an
    event needs to be handled.  The event is then dispatched
    to the appropriate handler.
    Inputs:  none
    Outputs: none
    ***********************************************************/
void Exec_run(void)
{
    unsigned char eventGenerated;

    while(1)
    {
        if (fastEventBitmask)
        {
            /* an event needing fast processing has been received */
            /* a received line needs to be processed...this
                needs to be processed as quickly as possible */
            if (fastEventBitmask & FEV_ACQUIRE_LINE_COMPLETE)
            {
                fastEventBitmask &= ~FEV_ACQUIRE_LINE_COMPLETE;
                FrameMgr_processLine();

                /* also check if serial data needs to be sent
                    out through UIMgr */
                UIMgr_transmitPendingData();

                /* we can't just call acquire line again here,
                    since we don't know if we need to acquire another
                    line or not (it depends on the FrameMgr to figure
                    this out) */
            }
            if (fastEventBitmask & FEV_PROCESS_LINE_COMPLETE)
            {
                fastEventBitmask &= ~FEV_PROCESS_LINE_COMPLETE;
                FrameMgr_acquireLine();
            }
        }
        else if (IS_DATA_IN_EVENT_FIFO() == TRUE)
        {
            DISABLE_INTS();
            eventGenerated = Exec_readEventFifo();
            ENABLE_INTS();
            switch(eventGenerated)
            {
            case (EV_DUMP_FRAME):
                FrameMgr_dispatchEvent(eventGenerated);
                break;

            case (EV_ENABLE_TRACKING):
                FrameMgr_dispatchEvent(eventGenerated);
                break;

            case (EV_DISABLE_TRACKING):
                FrameMgr_dispatchEvent(eventGenerated);
                break;

            case (EV_ACQUIRE_LINE_COMPLETE):
                FrameMgr_dispatchEvent(eventGenerated);
                UIMgr_dispatchEvent(eventGenerated);
                break;

            case (EV_ACQUIRE_FRAME_COMPLETE):
                FrameMgr_dispatchEvent(eventGenerated);
                break;

            case (EV_PROCESS_LINE_COMPLETE):
                FrameMgr_dispatchEvent(eventGenerated);
                break;

            case (EV_PROCESS_FRAME_COMPLETE):
                FrameMgr_dispatchEvent(eventGenerated);
                break;

            case (EV_SERIAL_DATA_RECEIVED):
                UIMgr_dispatchEvent(eventGenerated);
                FrameMgr_dispatchEvent(eventGenerated);
                break;

            case (EV_SERIAL_DATA_PENDING_TX):
                UIMgr_dispatchEvent(eventGenerated);
                break;

            default:
                break;
            }
        }
    }
}

/***********************************************************
    Function Name: Exec_readEventFifo
    Function Description: This function is responsible for
    reading a single event out of the event fifo.
    Inputs:  none
    Outputs: unsigned char-the data read
    ***********************************************************/
static unsigned char Exec_readEventFifo(void)
{
    unsigned char dataByte, tmpTail;

    DISABLE_INTS();
    /* just return the current tail from the tx fifo */
    dataByte = Exec_eventFifo[Exec_eventFifoTail];
    tmpTail = (Exec_eventFifoTail+1) & (EXEC_EVENT_FIFO_MASK);
    Exec_eventFifoTail = tmpTail;
    ENABLE_INTS();

    return(dataByte);
}

/***********************************************************
    Function Name: Exec_writeEventFifo
    Function Description: This function is responsible for
    writing a single event to the event fifo and
    updating the appropriate pointers.
    Inputs:  data - the byte to write to the Fifo
    Outputs: none
    ***********************************************************/
void Exec_writeEventFifo(unsigned char event)
{
    unsigned char tmpHead;

    DISABLE_INTS();
    Exec_eventFifo[Exec_eventFifoHead] = event;

    /* now move the head up */
    tmpHead = (Exec_eventFifoHead + 1) & (EXEC_EVENT_FIFO_MASK);
    Exec_eventFifoHead = tmpHead;
    ENABLE_INTS();
}