simh-testsetgenerator/3B2/3b2_dmac.h
Seth Morabito 9b62da6567 3B2-700 Initial Public Release
This commit introduces dozens of changes to make the 3B2-700 simulator
fully functional and ready for wider use. In addition to 3B2-700
availability, this commit includes a tremendous amount of refactoring
of the 3B2-400 and common code to make the project structure easier to
maintain and reason about.

One final important change: ROM files are no longer included in the
source code. 3B2 ROM images must be obtained separately and loaded
into the simulator before boot.

Changes:

- The 3b2 target has been aliased to 3b2-400
- The formerly named 3b2-600 project has become 3b2-700
- SCSI QIC tape support has been added to sim_scsi.c
- Header files have been reworked to reduce complexity of includes
- Common code has been consolidated
- Timer code has been unified
2022-09-15 14:15:28 -07:00

89 lines
3 KiB
C

/* 3b2_dmac.h: AM9517 DMA Controller
Copyright (c) 2021-2022, Seth J. Morabito
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use, copy,
modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
Except as contained in this notice, the name of the author shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from the author.
*/
#ifndef _3B2_DMAC_H_
#define _3B2_DMAC_H_
#include "3b2_defs.h"
#define DMA_XFER_VERIFY 0
#define DMA_XFER_WRITE 1 /* Write to memory from device */
#define DMA_XFER_READ 2 /* Read from memory to device */
#define DMA_IF_READ (IFBASE + IF_DATA_REG)
#define DMA_MODE(C) ((dma_state.channels[(C)].mode >> 6) & 3)
#define DMA_DECR(C) ((dma_state.channels[(C)].mode >> 5) & 1)
#define DMA_AUTOINIT(C) ((dma_state.channels[(C)].mode >> 4) & 1)
#define DMA_XFER(C) ((dma_state.channels[(C)].mode >> 2) & 3)
typedef struct {
uint8 mode; /* Channel mode */
uint16 page; /* Memory page */
uint16 addr; /* Original addr */
uint16 wcount; /* Original wcount */
uint16 addr_c; /* Current addr */
int32 wcount_c; /* Current word-count */
uint16 ptr; /* Pointer into memory */
} dma_channel;
typedef struct {
/* Byte (high/low) flip-flop */
uint8 bff;
/* Address and count registers for channels 0-3 */
dma_channel channels[4];
/* DMAC programmable registers */
uint8 command;
uint8 request;
uint8 mask;
uint8 status;
} DMA_STATE;
typedef struct {
uint8 channel;
uint32 service_address;
t_bool *drq;
void (*dma_handler)(uint8 channel, uint32 service_address);
void (*after_dma_callback)();
} dmac_dma_handler;
/* DMAC */
t_stat dmac_reset(DEVICE *dptr);
uint32 dmac_read(uint32 pa, size_t size);
void dmac_write(uint32 pa, uint32 val, size_t size);
void dmac_service_drqs();
void dmac_generic_dma(uint8 channel, uint32 service_address);
uint32 dma_address(uint8 channel, uint32 offset);
extern DMA_STATE dma_state;
#endif