nkeynes@939: /**
nkeynes@940:  * $Id$
nkeynes@939:  *
nkeynes@939:  * Dreamcast main SDRAM - access methods and timing controls. This is fairly
nkeynes@939:  * directly coupled to the SH4
nkeynes@939:  *
nkeynes@939:  * Copyright (c) 2005 Nathan Keynes.
nkeynes@939:  *
nkeynes@939:  * This program is free software; you can redistribute it and/or modify
nkeynes@939:  * it under the terms of the GNU General Public License as published by
nkeynes@939:  * the Free Software Foundation; either version 2 of the License, or
nkeynes@939:  * (at your option) any later version.
nkeynes@939:  *
nkeynes@939:  * This program is distributed in the hope that it will be useful,
nkeynes@939:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
nkeynes@939:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nkeynes@939:  * GNU General Public License for more details.
nkeynes@939:  */
nkeynes@939: 
nkeynes@939: #include "lxdream.h"
nkeynes@939: #include "mem.h"
nkeynes@939: #include "dreamcast.h"
nkeynes@991: #include "xlat/xltcache.h"
nkeynes@939: #include <string.h>
nkeynes@939: 
nkeynes@939: 
nkeynes@939: static int32_t FASTCALL ext_sdram_read_long( sh4addr_t addr )
nkeynes@939: {
nkeynes@939:     return *((int32_t *)(dc_main_ram + (addr&0x00FFFFFF)));
nkeynes@939: }
nkeynes@939: static int32_t FASTCALL ext_sdram_read_word( sh4addr_t addr )
nkeynes@939: {
nkeynes@939:     return SIGNEXT16(*((int16_t *)(dc_main_ram + (addr&0x00FFFFFF))));
nkeynes@939: }
nkeynes@939: static int32_t FASTCALL ext_sdram_read_byte( sh4addr_t addr )
nkeynes@939: {
nkeynes@939:     return SIGNEXT8(*((int16_t *)(dc_main_ram + (addr&0x00FFFFFF))));
nkeynes@939: }
nkeynes@939: static void FASTCALL ext_sdram_write_long( sh4addr_t addr, uint32_t val )
nkeynes@939: {
nkeynes@939:     *(uint32_t *)(dc_main_ram + (addr&0x00FFFFFF)) = val;
nkeynes@939:     xlat_invalidate_long(addr);
nkeynes@939: }
nkeynes@939: static void FASTCALL ext_sdram_write_word( sh4addr_t addr, uint32_t val )
nkeynes@939: {
nkeynes@939:     *(uint16_t *)(dc_main_ram + (addr&0x00FFFFFF)) = (uint16_t)val;
nkeynes@939:     xlat_invalidate_word(addr);
nkeynes@939: }
nkeynes@939: static void FASTCALL ext_sdram_write_byte( sh4addr_t addr, uint32_t val )
nkeynes@939: {
nkeynes@939:     *(uint8_t *)(dc_main_ram + (addr&0x00FFFFFF)) = (uint8_t)val;
nkeynes@939:     xlat_invalidate_word(addr);
nkeynes@939: }
nkeynes@939: static void FASTCALL ext_sdram_read_burst( unsigned char *dest, sh4addr_t addr )
nkeynes@939: {
nkeynes@939:     memcpy( dest, dc_main_ram+(addr&0x00FFFFFF), 32 );
nkeynes@939: }
nkeynes@939: static void FASTCALL ext_sdram_write_burst( sh4addr_t addr, unsigned char *src )
nkeynes@939: {
nkeynes@939:     memcpy( dc_main_ram+(addr&0x00FFFFFF), src, 32 );
nkeynes@939: }
nkeynes@939: 
nkeynes@939: struct mem_region_fn mem_region_sdram = { ext_sdram_read_long, ext_sdram_write_long, 
nkeynes@939:         ext_sdram_read_word, ext_sdram_write_word, 
nkeynes@939:         ext_sdram_read_byte, ext_sdram_write_byte, 
nkeynes@939:         ext_sdram_read_burst, ext_sdram_write_burst };