lxdream.org :: lxdream/src/sdram.c r940:81e0d3051d5f

tree revision 944:a4e31314bee1 lxdream-mem

filename	src/sdram.c
changeset	940:81e0d3051d5f
prev	939:6f2302afeb89
next	1067:d3c00ffccfcd
author	nkeynes
date	Mon Jan 05 04:17:20 2009 +0000 (15 years ago)
branch	lxdream-mem
permissions	-rw-r--r--
last change	Actually use sh4_user_address_space for user code

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     1 /**

     2  * $Id$

     3  *

     4  * Dreamcast main SDRAM - access methods and timing controls. This is fairly

     5  * directly coupled to the SH4

     6  *

     7  * Copyright (c) 2005 Nathan Keynes.

     8  *

     9  * This program is free software; you can redistribute it and/or modify

    10  * it under the terms of the GNU General Public License as published by

    11  * the Free Software Foundation; either version 2 of the License, or

    12  * (at your option) any later version.

    13  *

    14  * This program is distributed in the hope that it will be useful,

    15  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    17  * GNU General Public License for more details.

    18  */

    20 #include "lxdream.h"

    21 #include "mem.h"

    22 #include "dreamcast.h"

    23 #include <string.h>

    26 static int32_t FASTCALL ext_sdram_read_long( sh4addr_t addr )

    27 {

    28     return *((int32_t *)(dc_main_ram + (addr&0x00FFFFFF)));

    29 }

    30 static int32_t FASTCALL ext_sdram_read_word( sh4addr_t addr )

    31 {

    32     return SIGNEXT16(*((int16_t *)(dc_main_ram + (addr&0x00FFFFFF))));

    33 }

    34 static int32_t FASTCALL ext_sdram_read_byte( sh4addr_t addr )

    35 {

    36     return SIGNEXT8(*((int16_t *)(dc_main_ram + (addr&0x00FFFFFF))));

    37 }

    38 static void FASTCALL ext_sdram_write_long( sh4addr_t addr, uint32_t val )

    39 {

    40     *(uint32_t *)(dc_main_ram + (addr&0x00FFFFFF)) = val;

    41     xlat_invalidate_long(addr);

    42 }

    43 static void FASTCALL ext_sdram_write_word( sh4addr_t addr, uint32_t val )

    44 {

    45     *(uint16_t *)(dc_main_ram + (addr&0x00FFFFFF)) = (uint16_t)val;

    46     xlat_invalidate_word(addr);

    47 }

    48 static void FASTCALL ext_sdram_write_byte( sh4addr_t addr, uint32_t val )

    49 {

    50     *(uint8_t *)(dc_main_ram + (addr&0x00FFFFFF)) = (uint8_t)val;

    51     xlat_invalidate_word(addr);

    52 }

    53 static void FASTCALL ext_sdram_read_burst( unsigned char *dest, sh4addr_t addr )

    54 {

    55     memcpy( dest, dc_main_ram+(addr&0x00FFFFFF), 32 );

    56 }

    57 static void FASTCALL ext_sdram_write_burst( sh4addr_t addr, unsigned char *src )

    58 {

    59     memcpy( dc_main_ram+(addr&0x00FFFFFF), src, 32 );

    60 }

    62 struct mem_region_fn mem_region_sdram = { ext_sdram_read_long, ext_sdram_write_long,

    63         ext_sdram_read_word, ext_sdram_write_word,

    64         ext_sdram_read_byte, ext_sdram_write_byte,

    65         ext_sdram_read_burst, ext_sdram_write_burst };