src/include/spd.h

/*
 * This file is part of the LinuxBIOS project.
 *
 * Copyright (C) 2005 Digital Design Corporation
 * Copyright (C) 2006 Uwe Hermann <uwe@hermann-uwe.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

/*
 * Serial Presence Detect (SPD) data stored on SDRAM modules.
 *
 * Datasheet:
 *   - Name: PC SDRAM Serial Presence Detect (SPD) Specification
 *           Revision 1.2A, December, 1997
 *   - PDF: http://www.intel.com/design/chipsets/memory/spdsd12a.pdf
 *
 * Datasheet (alternative):
 *   - Name: SERIAL PRESENCE DETECT STANDARD, General Standard
 *           JEDEC Standard No. 21-C
 *   - PDF: http://www.jedec.org/download/search/4_01_02_00R9.PDF
 */

#ifndef _SPD_H_
#define _SPD_H_

/* Byte numbers. */
#define SPD_NUM_MANUFACTURER_BYTES          0  /* Number of bytes used by module manufacturer */
#define SPD_TOTAL_SPD_MEMORY_SIZE           1  /* Total SPD memory size */
#define SPD_MEMORY_TYPE                     2  /* (Fundamental) memory type */
#define SPD_NUM_ROWS                        3  /* Number of row address bits */
#define SPD_NUM_COLUMNS                     4  /* Number of column address bits */
#define SPD_NUM_DIMM_BANKS                  5  /* Number of module rows (banks) */
#define SPD_MODULE_DATA_WIDTH_LSB           6  /* Module data width (LSB) */
#define SPD_MODULE_DATA_WIDTH_MSB           7  /* Module data width (MSB) */
#define SPD_MODULE_VOLTAGE                  8  /* Module interface signal levels */
#define SPD_MIN_CYCLE_TIME_AT_CAS_MAX       9  /* SDRAM cycle time (highest CAS latency), RAS access time (tRAC) */
#define SPD_ACCESS_TIME_FROM_CLOCK          10 /* SDRAM access time from clock (highest CAS latency), CAS access time (Tac, tCAC) */
#define SPD_DIMM_CONFIG_TYPE                11 /* Module configuration type */
#define SPD_REFRESH                         12 /* Refresh rate/type */
#define SPD_PRIMARY_SDRAM_WIDTH             13 /* SDRAM width (primary SDRAM) */
#define SPD_ERROR_CHECKING_SDRAM_WIDTH      14 /* Error checking SDRAM (data) width */
#define SPD_MIN_CLOCK_DELAY_B2B_RAND_COLUMN 15 /* SDRAM device attributes, minimum clock delay for back to back random column */
#define SPD_SUPPORTED_BURST_LENGTHS         16 /* SDRAM device attributes, burst lengths supported */
#define SPD_NUM_BANKS_PER_SDRAM             17 /* SDRAM device attributes, number of banks on SDRAM device */
#define SPD_ACCEPTABLE_CAS_LATENCIES        18 /* SDRAM device attributes, CAS latency */
#define SPD_CS_LATENCY                      19 /* SDRAM device attributes, CS latency */
#define SPD_WE_LATENCY                      20 /* SDRAM device attributes, WE latency */
#define SPD_MODULE_ATTRIBUTES               21 /* SDRAM module attributes */
#define SPD_DEVICE_ATTRIBUTES_GENERAL       22 /* SDRAM device attributes, general */
#define SPD_SDRAM_CYCLE_TIME_2ND            23 /* SDRAM cycle time (2nd highest CAS latency) */
#define SPD_ACCESS_TIME_FROM_CLOCK_2ND      24 /* SDRAM access from clock (2nd highest CAS latency) */
#define SPD_SDRAM_CYCLE_TIME_3RD            25 /* SDRAM cycle time (3rd highest CAS latency) */
#define SPD_ACCESS_TIME_FROM_CLOCK_3RD      26 /* SDRAM access from clock (3rd highest CAS latency) */
#define SPD_MIN_ROW_PRECHARGE_TIME          27 /* Minimum row precharge time (Trp) */
#define SPD_MIN_ROWACTIVE_TO_ROWACTIVE      28 /* Minimum row active to row active (Trrd) */
#define SPD_MIN_RAS_TO_CAS_DELAY            29 /* Minimum RAS to CAS delay (Trcd) */
#define SPD_MIN_ACTIVE_TO_PRECHARGE_DELAY   30 /* Minimum RAS pulse width (Tras) */
#define SPD_DENSITY_OF_EACH_ROW_ON_MODULE   31 /* Density of each row on module */
#define SPD_CMD_SIGNAL_INPUT_SETUP_TIME     32 /* Command and address signal input setup time */
#define SPD_CMD_SIGNAL_INPUT_HOLD_TIME      33 /* Command and address signal input hold time */
#define SPD_DATA_SIGNAL_INPUT_SETUP_TIME    34 /* Data signal input setup time */
#define SPD_DATA_SIGNAL_INPUT_HOLD_TIME     35 /* Data signal input hold time */
#define SPD_SPD_DATA_REVISION_CODE          62 /* SPD data revision code */
#define SPD_CHECKSUM_FOR_BYTES_0_TO_62      63 /* Checksum for bytes 0-62 */
#define SPD_MANUFACTURER_JEDEC_ID_CODE      64 /* Manufacturer's JEDEC ID code, per EIA/JEP106 (bytes 64-71) */
#define SPD_MANUFACTURING_LOCATION          72 /* Manufacturing location */
#define SPD_MANUFACTURER_PART_NUMBER        73 /* Manufacturer's part number, in 6-bit ASCII (bytes 73-90) */
#define SPD_REVISION_CODE                   91 /* Revision code (bytes 91-92) */
#define SPD_MANUFACTURING_DATE              93 /* Manufacturing date (byte 93: year, byte 94: week) */
#define SPD_ASSEMBLY_SERIAL_NUMBER          95 /* Assembly serial number (bytes 95-98) */
#define SPD_MANUFACTURER_SPECIFIC_DATA      99 /* Manufacturer specific data (bytes 99-125) */
#define SPD_INTEL_SPEC_FOR_FREQUENCY       126 /* Intel specification for frequency */
#define SPD_INTEL_SPEC_100_MHZ             127 /* Intel specification details for 100MHz support */

/* DRAM specifications use the following naming conventions for SPD locations */
#define SPD_tRP                             SPD_MIN_ROW_PRECHARGE_TIME
#define SPD_tRRD                            SPD_MIN_ROWACTIVE_TO_ROWACTIVE
#define SPD_tRCD                            SPD_MIN_RAS_TO_CAS_DELAY
#define SPD_tRAS                            SPD_MIN_ACTIVE_TO_PRECHARGE_DELAY
#define SPD_BANK_DENSITY                    SPD_DENSITY_OF_EACH_ROW_ON_MODULE
#define SPD_ADDRESS_CMD_HOLD                SPD_CMD_SIGNAL_INPUT_HOLD_TIME
#define SPD_tRC				    41	/* SDRAM Device Minimum Active to Active/Auto Refresh Time (tRC) */
#define SPD_tRFC			    42	/* SDRAM Device Minimum Auto Refresh to Active/Auto Refresh (tRFC) */


/* SPD_MEMORY_TYPE values. */
#define SPD_MEMORY_TYPE_FPM_DRAM         1
#define SPD_MEMORY_TYPE_EDO              2
#define SPD_MEMORY_TYPE_PIPELINED_NIBBLE 3
#define SPD_MEMORY_TYPE_SDRAM            4
#define SPD_MEMORY_TYPE_MULTIPLEXED_ROM  5
#define SPD_MEMORY_TYPE_SGRAM_DDR        6
#define SPD_MEMORY_TYPE_SDRAM_DDR        7
#define SPD_MEMORY_TYPE_SDRAM_DDR2       8

/* SPD_MODULE_VOLTAGE values. */
#define SPD_VOLTAGE_TTL                  0 /* 5.0 Volt/TTL */
#define SPD_VOLTAGE_LVTTL                1 /* LVTTL */
#define SPD_VOLTAGE_HSTL                 2 /* HSTL 1.5 */
#define SPD_VOLTAGE_SSTL3                3 /* SSTL 3.3 */
#define SPD_VOLTAGE_SSTL2                4 /* SSTL 2.5 */

/* SPD_DIMM_CONFIG_TYPE values. */
#define ERROR_SCHEME_NONE                0
#define ERROR_SCHEME_PARITY              1
#define ERROR_SCHEME_ECC                 2

/* SPD_ACCEPTABLE_CAS_LATENCIES values. */
// TODO: Check values.
#define SPD_CAS_LATENCY_1_0              0x01
#define SPD_CAS_LATENCY_1_5              0x02
#define SPD_CAS_LATENCY_2_0              0x04
#define SPD_CAS_LATENCY_2_5              0x08
#define SPD_CAS_LATENCY_3_0              0x10
#define SPD_CAS_LATENCY_3_5              0x20
#define SPD_CAS_LATENCY_4_0              0x40

/* SPD_SUPPORTED_BURST_LENGTHS values. */
#define SPD_BURST_LENGTH_1               1
#define SPD_BURST_LENGTH_2               2
#define SPD_BURST_LENGTH_4               4
#define SPD_BURST_LENGTH_8               8
#define SPD_BURST_LENGTH_PAGE            (1 << 7)

/* SPD_MODULE_ATTRIBUTES values. */
#define MODULE_BUFFERED                  1
#define MODULE_REGISTERED                2

#endif /* _SPD_H_ */