2 * This file is part of the coreboot project.
4 * Copyright (C) 2005 Digital Design Corporation
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 * sdram_mode.h: Definitions for SDRAM Mode Register and Extended Mode Register
25 #ifndef __SDRAMMODE_H_DEFINED
26 #define __SDRAMMODE_H_DEFINED
28 // SDRAM Mode Register definitions, per JESD79D
29 // These are transmitted via A0-A13
32 #define SDRAM_BURST_2 (1<<0)
33 #define SDRAM_BURST_4 (2<<0)
34 #define SDRAM_BURST_8 (3<<0)
36 #define SDRAM_BURST_SEQUENTIAL (0<<3)
37 #define SDRAM_BURST_INTERLEAVED (1<<3)
39 #define SDRAM_CAS_2_0 (2<<4)
40 #define SDRAM_CAS_3_0 (3<<4) /* Optional for DDR 200-333 */
41 #define SDRAM_CAS_1_5 (5<<4) /* Optional */
42 #define SDRAM_CAS_2_5 (6<<4)
43 #define SDRAM_CAS_MASK (7<<4)
45 #define SDRAM_MODE_NORMAL (0 << 7)
46 #define SDRAM_MODE_TEST (1 << 7)
47 #define SDRAM_MODE_DLL_RESET (2 << 7)
49 // Extended Mode Register
51 #define SDRAM_EXTMODE_DLL_ENABLE (0 << 0)
52 #define SDRAM_EXTMODE_DLL_DISABLE (1 << 0)
54 #define SDRAM_EXTMODE_DRIVE_NORMAL (0 << 1)
55 #define SDRAM_EXTMODE_DRIVE_WEAK (1 << 1) /* Optional */
57 #endif // __SDRAMMODE_H_DEFINED