reactos/subsystems/mvdm/ntvdm/hardware/dma.h

   1 /*
   2  * COPYRIGHT:       GPL - See COPYING in the top level directory
   3  * PROJECT:         ReactOS Virtual DOS Machine
   4  * FILE:            dma.h
   5  * PURPOSE:         Direct Memory Access Controller emulation -
   6  *                  i8237A compatible with 74LS612 Memory Mapper extension
   7  * PROGRAMMERS:     Hermes Belusca-Maito (hermes.belusca@sfr.fr)
   8  */
   9
  10 #ifndef _DMA_H_
  11 #define _DMA_H_
  12
  13 /* INCLUDES *******************************************************************/
  14
  15 #include "ntvdm.h"
  16
  17 /* DEFINES ********************************************************************/
  18
  19 #define DMA_CONTROLLERS         2
  20 #define DMA_CONTROLLER_CHANNELS 4 // Each DMA controller has 4 channels
  21
  22 typedef struct _DMA_CHANNEL
  23 {
  24     WORD BaseAddress;
  25     WORD BaseWordCnt;
  26     WORD CurrAddress;
  27     WORD CurrWordCnt;
  28     BYTE Mode;
  29 } DMA_CHANNEL, *PDMA_CHANNEL;
  30
  31 typedef struct _DMA_CONTROLLER
  32 {
  33     DMA_CHANNEL DmaChannel[DMA_CONTROLLER_CHANNELS];
  34
  35     WORD TempAddress;
  36     WORD TempWordCnt;
  37
  38     BYTE TempReg;
  39
  40     BYTE Command;
  41     BYTE Request;
  42     BYTE Mask;
  43     BYTE Status;
  44
  45     BOOLEAN FlipFlop; // 0: LSB ; 1: MSB
  46
  47 } DMA_CONTROLLER, *PDMA_CONTROLLER;
  48
  49 /* 74LS612 Memory Mapper extension */
  50 typedef struct _DMA_PAGE_REGISTER
  51 {
  52     BYTE Page;
  53 } DMA_PAGE_REGISTER, *PDMA_PAGE_REGISTER;
  54
  55 // The 74LS612 contains 16 bytes, each of them being a page register.
  56 // They are accessible via ports 0x80 through 0x8F .
  57
  58 /* FUNCTIONS ******************************************************************/
  59
  60 VOID DmaInitialize(VOID);
  61
  62 #endif // _DMA_H_
  63
  64 /* EOF */