buffer.h

simulink real-time workshop for dragon12 development board from

/******************************************************************************/
/*                                                                            */
/* Name: BUFFER.H - Module to manage a circular buffer in the microcontroller */
/*                                                                            */
/* Author: Sven Rebeschiess                                                   */
/* Date: 10.8.1999                                                            */
/*                                                                            */
/* Modifications: F. Wornle (FW-mn-yr)                                        */
/* Latest change: FW-12-02                                                    */
/*                                                                            */
/******************************************************************************/

#ifndef _MC_BUFFER_H_
#define _MC_BUFFER_H_

#include <stdlib.h>          /* free, malloc, NULL */

#ifdef DEBUGSCI0
#include "mc_signal.h"       /* global debug variable mallocTotalBytes */
#endif


#ifndef _MY_TYPES_H_
  #define _MY_TYPES_H
  #define BOOLEAN	char
  #define BYTE	unsigned char
  #define WORD	unsigned  int
  #define DWORD	unsigned  long

  #ifndef TRUE
	#define TRUE (1)
  #endif
  #ifndef FALSE
    #define FALSE (0)
  #endif
#endif


// ring buffer administration structure ('BufferTyp')
struct BufferTyp
{
  WORD First;                /* Ringpuffer-Zeiger auf den Anfang der Elemente */
  WORD Last;                 /* Ringpuffer-Zeiger auf das Ende der Elemente   */
  WORD Count;                /* Anzahl der im Ringpuffer gespeicherten Elem.  */
  //WORD RecordCount;          /* Anzahl der im Ringpuffer gespeicherten Records (FW-06-01) */
  WORD BufLength;            /* L鋘ge des Ringpuffers                         */
  BYTE ElemLength;           /* L鋘ge jedes Puffereintrages in Bytes          */
  BYTE j;                    /* Hilfs-Schleifenvariable                       */
  char *bp;                  /* Hilfszeiger                                   */
  char *Buffer;              /* Zeiger auf den eigentlichen Ringpuffer        */
};


// 'RecordAvailable()' returns TRUE if the buffer stores at least one whole record; otherwise it returns FALSE
// FW-06-01
//#define RecordAvailable(BPtr) (BPtr->RecordCount > 0)


// 'IncRecordCount()' increments 'RecordCount' by '1'
//#define IncRecordCount(BPtr) (BPtr->RecordCount += 1)


// 'DecRecordCount()' decrements 'RecordCount' by '1'
//#define DecRecordCount(BPtr) (BPtr->RecordCount -= 1)


// 'IncCount()' increments 'count' by '1' taking into account the maximum buffer length
// (count => ..., MaxLength-1, MaxLength, 0, 1, 2, ...)
#define IncCount(Count,MaxLength) ((++Count)%MaxLength)


// 'NotEmptyBuffer()' returns TRUE if the buffer is empty; otherwise it returns FALSE
#define NotEmptyBuffer(BPtr) (BPtr->Count > 0)


// 'NotFullBuffer()' returns FALSE if the buffer is full; otherwise it returns TRUE
#define NotFullBuffer(BPtr) (BPtr->Count < BPtr->BufLength)


// 'Buffercounter()' returns the current counter value of the buffer
#define Buffercounter(BPtr) (BPtr->Count)


// 'InitBuffer()' initialises a ring buffer of a specified type (e. g. 'char')
// the required memory is allocated dynamically on the HEAP (malloc)
#define InitBuffer(BPtr,BufferMax,Typ) \
		if((BPtr = (struct BufferTyp *)malloc(sizeof(struct BufferTyp))) == NULL)\
		   abort_LED(80);\
		else\
		  {\
		   BPtr->ElemLength = (BYTE)(sizeof(Typ));\
		   if((BPtr->Buffer = (char *)malloc(BPtr->ElemLength * BufferMax)) == NULL)\
			abort_LED(81);\
		   else\
		   {\
			ClearBuffer(BPtr);\
			BPtr->BufLength = BufferMax;\
		   }\
		  }


// 'RemoveBuffer()' destroys a given ring buffer and returns all allocated memory to the HEAP
#define RemoveBuffer(BPtr) \
		free((void *)BPtr->Buffer);\
		free((void *)BPtr)


// 'ClearBuffer()' deletes all elements in a buffer; the buffer is empty again
#define ClearBuffer(BPtr) \
		BPtr->First = 0;\
		BPtr->Last = 0;\
		BPtr->Count = 0;//\
		//BPtr->RecordCount = 0


// 'InBuffer()' stores a value in the (ring) buffer
// (this macro fails with an error code '82' if the buffer is full)
#define InBuffer(Wert,BPtr) \
		if(NotFullBuffer(BPtr))\
		{\
			BPtr->bp = (char*)&Wert;\
			for (BPtr->j = 0; BPtr->j < BPtr->ElemLength; BPtr->j++)\
			   BPtr->Buffer[BPtr->ElemLength * BPtr->First + BPtr->j] = *(BPtr->bp + BPtr->j);\
			BPtr->First = IncCount(BPtr->First,BPtr->BufLength);\
			BPtr->Count++ ;\
		}\
		else\
		{\
		     abort_LED(82);\
		}


// 'OutBuffer()' fetches a value from the (ring) buffer
// (this macro fails with an error code of '83' in case the buffer is empty)
#define OutBuffer(BPtr,Wert,Typ) \
		if(NotEmptyBuffer(BPtr))\
		{\
		    Wert = *(Typ*)&(BPtr->Buffer[BPtr->ElemLength * BPtr->Last]);\
		    BPtr->Last = IncCount(BPtr->Last,BPtr->BufLength);\
		    BPtr->Count-- ;\
		}\
		else\
		{\
		    Wert = 0;\
		    abort_LED(83);\
		}


#endif	/* _MC_BUFFER_H_ */