//---------------------------------------------------------------------------
// L361.C
// Using the 80C188XL internal DMA channel 0 for implementing a 
// Memory to Memory tansfer, i.e., copy one string to another.
// Unsynchonized transfer terminates without interrupt generation.
// 
// C/C++ code for the SBC188 board.
// C.P. Diduch, March 1999.
//---------------------------------------------------------------------------
#define TRUE    1

#define D0SRCL  0xFFC0          // 80C188 DMA0 SRC address: lo 16-bits.
#define D0SRCH  0xFFC2          // 80C188 DMA0 SRC address: hi 4-bits.
#define D0DSTL  0xFFC4          // 80C188 DMA0 DST address: lo 16-bits.
#define D0DSTH  0xFFC6          // 80C188 DMA0 DST address: hi 4-bits.
#define D0TC    0xFFC8          // 80C188 DMA0 terminal count register.
#define D0CON   0xFFCA          // 80C188 DMA0 control register.

#include <dos.h>
#include <conio.h>


void delay(unsigned MILLISECS); // Function prototypes.
void dma_mem_mem(char *x, char *y, unsigned z, unsigned NO_BYTES);

//---------------------------------------------------------------------------
void main(void)
{
char DATA[] = {1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3, \
               4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6};
char BUFF[60];
unsigned SA;

asm{
   mov SA, ds                   // Get segment address of BUFF[] and DATA[]. 
   }

// Initialize and arm DMA0 to transfer 60 bytes from array DATA[]
// to array BUFF[].

dma_mem_mem(&BUFF[0], &DATA[0], SA, 60); 
delay(1000);
}

//---------------------------------------------------------------------------     
void dma_mem_mem(char *DST, char *SRC, unsigned SA, unsigned NO_BYTES)
{
long PA;
unsigned LO, HI;

PA = (16* (long) SA) + (unsigned) SRC;
LO = (unsigned) PA;
HI = (unsigned) (PA >> 16);
outport(D0SRCL, LO);
outport(D0SRCH, HI);

PA = (16* (long) SA) + (unsigned) DST;
LO = (unsigned) PA;
HI = (unsigned) (PA >> 16);
outport(D0DSTL, LO); 
outport(D0DSTH, HI);
outport(D0TC, NO_BYTES);
                                // with interrupt.
outport(D0CON, 0xB606);         // Unsynchronize transfer terminates
                                // with NO interrupt
}

//---------------------------------------------------------------------------
void delay(unsigned MILLISECS)
{
unsigned M;
while (MILLISECS != 0) {
   M = 1000;
   while (M != 0) {M--;}
   MILLISECS--;
   }
}