drivers/ddr/fsl/ddr3_dimm_params.c - github/trini/u-boot - Gitiles

 /*
  * Copyright 2008-2012 Freescale Semiconductor, Inc.
  *	Dave Liu <daveliu@freescale.com>
  *
  * calculate the organization and timing parameter
  * from ddr3 spd, please refer to the spec
  * JEDEC standard No.21-C 4_01_02_11R18.pdf
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * Version 2 as published by the Free Software Foundation.
  */

 #include <common.h>
 #include <fsl_ddr_sdram.h>

 #include <fsl_ddr.h>

 /*
  * Calculate the Density of each Physical Rank.
  * Returned size is in bytes.
  *
  * each rank size =
  * sdram capacity(bit) / 8 * primary bus width / sdram width
  *
  * where: sdram capacity  = spd byte4[3:0]
  *        primary bus width = spd byte8[2:0]
  *        sdram width = spd byte7[2:0]
  *
  * SPD byte4 - sdram density and banks
  *	bit[3:0]	size(bit)	size(byte)
  *	0000		256Mb		32MB
  *	0001		512Mb		64MB
  *	0010		1Gb		128MB
  *	0011		2Gb		256MB
  *	0100		4Gb		512MB
  *	0101		8Gb		1GB
  *	0110		16Gb		2GB
  *
  * SPD byte8 - module memory bus width
  * 	bit[2:0]	primary bus width
  *	000		8bits
  * 	001		16bits
  * 	010		32bits
  * 	011		64bits
  *
  * SPD byte7 - module organiztion
  * 	bit[2:0]	sdram device width
  * 	000		4bits
  * 	001		8bits
  * 	010		16bits
  * 	011		32bits
  *
  */
 static unsigned long long
 compute_ranksize(const ddr3_spd_eeprom_t *spd)
 {
 	unsigned long long bsize;

 	int nbit_sdram_cap_bsize = 0;
 	int nbit_primary_bus_width = 0;
 	int nbit_sdram_width = 0;

 	if ((spd->density_banks & 0xf) < 7)
 		nbit_sdram_cap_bsize = (spd->density_banks & 0xf) + 28;
 	if ((spd->bus_width & 0x7) < 4)
 		nbit_primary_bus_width = (spd->bus_width & 0x7) + 3;
 	if ((spd->organization & 0x7) < 4)
 		nbit_sdram_width = (spd->organization & 0x7) + 2;

 	bsize = 1ULL << (nbit_sdram_cap_bsize - 3
 		    + nbit_primary_bus_width - nbit_sdram_width);

 	debug("DDR: DDR III rank density = 0x%16llx\n", bsize);

 	return bsize;
 }

 /*
  * ddr_compute_dimm_parameters for DDR3 SPD
  *
  * Compute DIMM parameters based upon the SPD information in spd.
  * Writes the results to the dimm_params_t structure pointed by pdimm.
  *
  */
 unsigned int
 ddr_compute_dimm_parameters(const ddr3_spd_eeprom_t *spd,
 			     dimm_params_t *pdimm,
 			     unsigned int dimm_number)
 {
 	unsigned int retval;
 	unsigned int mtb_ps;
 	int ftb_10th_ps;
 	int i;

 	if (spd->mem_type) {
 		if (spd->mem_type != SPD_MEMTYPE_DDR3) {
 			printf("DIMM %u: is not a DDR3 SPD.\n", dimm_number);
 			return 1;
 		}
 	} else {
 		memset(pdimm, 0, sizeof(dimm_params_t));
 		return 1;
 	}

 	retval = ddr3_spd_check(spd);
 	if (retval) {
 		printf("DIMM %u: failed checksum\n", dimm_number);
 		return 2;
 	}

 	/*
 	 * The part name in ASCII in the SPD EEPROM is not null terminated.
 	 * Guarantee null termination here by presetting all bytes to 0
 	 * and copying the part name in ASCII from the SPD onto it
 	 */
 	memset(pdimm->mpart, 0, sizeof(pdimm->mpart));
 	if ((spd->info_size_crc & 0xF) > 1)
 		memcpy(pdimm->mpart, spd->mpart, sizeof(pdimm->mpart) - 1);

 	/* DIMM organization parameters */
 	pdimm->n_ranks = ((spd->organization >> 3) & 0x7) + 1;
 	pdimm->rank_density = compute_ranksize(spd);
 	pdimm->capacity = pdimm->n_ranks * pdimm->rank_density;
 	pdimm->primary_sdram_width = 1 << (3 + (spd->bus_width & 0x7));
 	if ((spd->bus_width >> 3) & 0x3)
 		pdimm->ec_sdram_width = 8;
 	else
 		pdimm->ec_sdram_width = 0;
 	pdimm->data_width = pdimm->primary_sdram_width
 			  + pdimm->ec_sdram_width;
 	pdimm->device_width = 1 << ((spd->organization & 0x7) + 2);

 	/* These are the types defined by the JEDEC DDR3 SPD spec */
 	pdimm->mirrored_dimm = 0;
 	pdimm->registered_dimm = 0;
 	switch (spd->module_type & DDR3_SPD_MODULETYPE_MASK) {
 	case DDR3_SPD_MODULETYPE_RDIMM:
 	case DDR3_SPD_MODULETYPE_MINI_RDIMM:
 	case DDR3_SPD_MODULETYPE_72B_SO_RDIMM:
 		/* Registered/buffered DIMMs */
 		pdimm->registered_dimm = 1;
 		for (i = 0; i < 16; i += 2) {
 			u8 rcw = spd->mod_section.registered.rcw[i/2];
 			pdimm->rcw[i]   = (rcw >> 0) & 0x0F;
 			pdimm->rcw[i+1] = (rcw >> 4) & 0x0F;
 		}
 		break;

 	case DDR3_SPD_MODULETYPE_UDIMM:
 	case DDR3_SPD_MODULETYPE_SO_DIMM:
 	case DDR3_SPD_MODULETYPE_MICRO_DIMM:
 	case DDR3_SPD_MODULETYPE_MINI_UDIMM:
 	case DDR3_SPD_MODULETYPE_MINI_CDIMM:
 	case DDR3_SPD_MODULETYPE_72B_SO_UDIMM:
 	case DDR3_SPD_MODULETYPE_72B_SO_CDIMM:
 	case DDR3_SPD_MODULETYPE_LRDIMM:
 	case DDR3_SPD_MODULETYPE_16B_SO_DIMM:
 	case DDR3_SPD_MODULETYPE_32B_SO_DIMM:
 		/* Unbuffered DIMMs */
 		if (spd->mod_section.unbuffered.addr_mapping & 0x1)
 			pdimm->mirrored_dimm = 1;
 		break;

 	default:
 		printf("unknown module_type 0x%02X\n", spd->module_type);
 		return 1;
 	}

 	/* SDRAM device parameters */
 	pdimm->n_row_addr = ((spd->addressing >> 3) & 0x7) + 12;
 	pdimm->n_col_addr = (spd->addressing & 0x7) + 9;
 	pdimm->n_banks_per_sdram_device = 8 << ((spd->density_banks >> 4) & 0x7);

 	/*
 	 * The SPD spec has not the ECC bit,
 	 * We consider the DIMM as ECC capability
 	 * when the extension bus exist
 	 */
 	if (pdimm->ec_sdram_width)
 		pdimm->edc_config = 0x02;
 	else
 		pdimm->edc_config = 0x00;

 	/*
 	 * The SPD spec has not the burst length byte
 	 * but DDR3 spec has nature BL8 and BC4,
 	 * BL8 -bit3, BC4 -bit2
 	 */
 	pdimm->burst_lengths_bitmask = 0x0c;
 	pdimm->row_density = __ilog2(pdimm->rank_density);

 	/* MTB - medium timebase
 	 * The unit in the SPD spec is ns,
 	 * We convert it to ps.
 	 * eg: MTB = 0.125ns (125ps)
 	 */
 	mtb_ps = (spd->mtb_dividend * 1000) /spd->mtb_divisor;
 	pdimm->mtb_ps = mtb_ps;

 	/*
 	 * FTB - fine timebase
 	 * use 1/10th of ps as our unit to avoid floating point
 	 * eg, 10 for 1ps, 25 for 2.5ps, 50 for 5ps
 	 */
 	ftb_10th_ps =
 		((spd->ftb_div & 0xf0) >> 4) * 10 / (spd->ftb_div & 0x0f);
 	pdimm->ftb_10th_ps = ftb_10th_ps;
 	/*
 	 * sdram minimum cycle time
 	 * we assume the MTB is 0.125ns
 	 * eg:
 	 * tck_min=15 MTB (1.875ns) ->DDR3-1066
 	 *        =12 MTB (1.5ns) ->DDR3-1333
 	 *        =10 MTB (1.25ns) ->DDR3-1600
 	 */
 	pdimm->tckmin_x_ps = spd->tck_min * mtb_ps +
 		(spd->fine_tck_min * ftb_10th_ps) / 10;

 	/*
 	 * CAS latency supported
 	 * bit4 - CL4
 	 * bit5 - CL5
 	 * bit18 - CL18
 	 */
 	pdimm->caslat_x  = ((spd->caslat_msb << 8) | spd->caslat_lsb) << 4;

 	/*
 	 * min CAS latency time
 	 * eg: taa_min =
 	 * DDR3-800D	100 MTB (12.5ns)
 	 * DDR3-1066F	105 MTB (13.125ns)
 	 * DDR3-1333H	108 MTB (13.5ns)
 	 * DDR3-1600H	90 MTB (11.25ns)
 	 */
 	pdimm->taa_ps = spd->taa_min * mtb_ps +
 		(spd->fine_taa_min * ftb_10th_ps) / 10;

 	/*
 	 * min write recovery time
 	 * eg:
 	 * twr_min = 120 MTB (15ns) -> all speed grades.
 	 */
 	pdimm->twr_ps = spd->twr_min * mtb_ps;

 	/*
 	 * min RAS to CAS delay time
 	 * eg: trcd_min =
 	 * DDR3-800	100 MTB (12.5ns)
 	 * DDR3-1066F	105 MTB (13.125ns)
 	 * DDR3-1333H	108 MTB (13.5ns)
 	 * DDR3-1600H	90 MTB (11.25)
 	 */
 	pdimm->trcd_ps = spd->trcd_min * mtb_ps +
 		(spd->fine_trcd_min * ftb_10th_ps) / 10;

 	/*
 	 * min row active to row active delay time
 	 * eg: trrd_min =
 	 * DDR3-800(1KB page)	80 MTB (10ns)
 	 * DDR3-1333(1KB page)	48 MTB (6ns)
 	 */
 	pdimm->trrd_ps = spd->trrd_min * mtb_ps;

 	/*
 	 * min row precharge delay time
 	 * eg: trp_min =
 	 * DDR3-800D	100 MTB (12.5ns)
 	 * DDR3-1066F	105 MTB (13.125ns)
 	 * DDR3-1333H	108 MTB (13.5ns)
 	 * DDR3-1600H	90 MTB (11.25ns)
 	 */
 	pdimm->trp_ps = spd->trp_min * mtb_ps +
 		(spd->fine_trp_min * ftb_10th_ps) / 10;

 	/* min active to precharge delay time
 	 * eg: tRAS_min =
 	 * DDR3-800D	300 MTB (37.5ns)
 	 * DDR3-1066F	300 MTB (37.5ns)
 	 * DDR3-1333H	288 MTB (36ns)
 	 * DDR3-1600H	280 MTB (35ns)
 	 */
 	pdimm->tras_ps = (((spd->tras_trc_ext & 0xf) << 8) | spd->tras_min_lsb)
 			* mtb_ps;
 	/*
 	 * min active to actice/refresh delay time
 	 * eg: tRC_min =
 	 * DDR3-800D	400 MTB (50ns)
 	 * DDR3-1066F	405 MTB (50.625ns)
 	 * DDR3-1333H	396 MTB (49.5ns)
 	 * DDR3-1600H	370 MTB (46.25ns)
 	 */
 	pdimm->trc_ps = (((spd->tras_trc_ext & 0xf0) << 4) | spd->trc_min_lsb)
 			* mtb_ps + (spd->fine_trc_min * ftb_10th_ps) / 10;
 	/*
 	 * min refresh recovery delay time
 	 * eg: tRFC_min =
 	 * 512Mb	720 MTB (90ns)
 	 * 1Gb		880 MTB (110ns)
 	 * 2Gb		1280 MTB (160ns)
 	 */
 	pdimm->trfc_ps = ((spd->trfc_min_msb << 8) | spd->trfc_min_lsb)
 			* mtb_ps;
 	/*
 	 * min internal write to read command delay time
 	 * eg: twtr_min = 40 MTB (7.5ns) - all speed bins.
 	 * tWRT is at least 4 mclk independent of operating freq.
 	 */
 	pdimm->twtr_ps = spd->twtr_min * mtb_ps;

 	/*
 	 * min internal read to precharge command delay time
 	 * eg: trtp_min = 40 MTB (7.5ns) - all speed bins.
 	 * tRTP is at least 4 mclk independent of operating freq.
 	 */
 	pdimm->trtp_ps = spd->trtp_min * mtb_ps;

 	/*
 	 * Average periodic refresh interval
 	 * tREFI = 7.8 us at normal temperature range
 	 *       = 3.9 us at ext temperature range
 	 */
 	pdimm->refresh_rate_ps = 7800000;
 	if ((spd->therm_ref_opt & 0x1) && !(spd->therm_ref_opt & 0x2)) {
 		pdimm->refresh_rate_ps = 3900000;
 		pdimm->extended_op_srt = 1;
 	}

 	/*
 	 * min four active window delay time
 	 * eg: tfaw_min =
 	 * DDR3-800(1KB page)	320 MTB (40ns)
 	 * DDR3-1066(1KB page)	300 MTB (37.5ns)
 	 * DDR3-1333(1KB page)	240 MTB (30ns)
 	 * DDR3-1600(1KB page)	240 MTB (30ns)
 	 */
 	pdimm->tfaw_ps = (((spd->tfaw_msb & 0xf) << 8) | spd->tfaw_min)
 			* mtb_ps;

 	return 0;
 }
	/*
	* Copyright 2008-2012 Freescale Semiconductor, Inc.
	* Dave Liu <daveliu@freescale.com>
	*
	* calculate the organization and timing parameter
	* from ddr3 spd, please refer to the spec
	* JEDEC standard No.21-C 4_01_02_11R18.pdf
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* Version 2 as published by the Free Software Foundation.
	*/

	#include <common.h>
	#include <fsl_ddr_sdram.h>

	#include <fsl_ddr.h>

	/*
	* Calculate the Density of each Physical Rank.
	* Returned size is in bytes.
	*
	* each rank size =
	* sdram capacity(bit) / 8 * primary bus width / sdram width
	*
	* where: sdram capacity = spd byte4[3:0]
	* primary bus width = spd byte8[2:0]
	* sdram width = spd byte7[2:0]
	*
	* SPD byte4 - sdram density and banks
	* bit[3:0] size(bit) size(byte)
	* 0000 256Mb 32MB
	* 0001 512Mb 64MB
	* 0010 1Gb 128MB
	* 0011 2Gb 256MB
	* 0100 4Gb 512MB
	* 0101 8Gb 1GB
	* 0110 16Gb 2GB
	*
	* SPD byte8 - module memory bus width
	* bit[2:0] primary bus width
	* 000 8bits
	* 001 16bits
	* 010 32bits
	* 011 64bits
	*
	* SPD byte7 - module organiztion
	* bit[2:0] sdram device width
	* 000 4bits
	* 001 8bits
	* 010 16bits
	* 011 32bits
	*
	*/
	static unsigned long long
	compute_ranksize(const ddr3_spd_eeprom_t *spd)
	{
	unsigned long long bsize;

	int nbit_sdram_cap_bsize = 0;
	int nbit_primary_bus_width = 0;
	int nbit_sdram_width = 0;

	if ((spd->density_banks & 0xf) < 7)
	nbit_sdram_cap_bsize = (spd->density_banks & 0xf) + 28;
	if ((spd->bus_width & 0x7) < 4)
	nbit_primary_bus_width = (spd->bus_width & 0x7) + 3;
	if ((spd->organization & 0x7) < 4)
	nbit_sdram_width = (spd->organization & 0x7) + 2;

	bsize = 1ULL << (nbit_sdram_cap_bsize - 3
	+ nbit_primary_bus_width - nbit_sdram_width);

	debug("DDR: DDR III rank density = 0x%16llx\n", bsize);

	return bsize;
	}

	/*
	* ddr_compute_dimm_parameters for DDR3 SPD
	*
	* Compute DIMM parameters based upon the SPD information in spd.
	* Writes the results to the dimm_params_t structure pointed by pdimm.
	*
	*/
	unsigned int
	ddr_compute_dimm_parameters(const ddr3_spd_eeprom_t *spd,
	dimm_params_t *pdimm,
	unsigned int dimm_number)
	{
	unsigned int retval;
	unsigned int mtb_ps;
	int ftb_10th_ps;
	int i;

	if (spd->mem_type) {
	if (spd->mem_type != SPD_MEMTYPE_DDR3) {
	printf("DIMM %u: is not a DDR3 SPD.\n", dimm_number);
	return 1;
	}
	} else {
	memset(pdimm, 0, sizeof(dimm_params_t));
	return 1;
	}

	retval = ddr3_spd_check(spd);
	if (retval) {
	printf("DIMM %u: failed checksum\n", dimm_number);
	return 2;
	}

	/*
	* The part name in ASCII in the SPD EEPROM is not null terminated.
	* Guarantee null termination here by presetting all bytes to 0
	* and copying the part name in ASCII from the SPD onto it
	*/
	memset(pdimm->mpart, 0, sizeof(pdimm->mpart));
	if ((spd->info_size_crc & 0xF) > 1)
	memcpy(pdimm->mpart, spd->mpart, sizeof(pdimm->mpart) - 1);

	/* DIMM organization parameters */
	pdimm->n_ranks = ((spd->organization >> 3) & 0x7) + 1;
	pdimm->rank_density = compute_ranksize(spd);
	pdimm->capacity = pdimm->n_ranks * pdimm->rank_density;
	pdimm->primary_sdram_width = 1 << (3 + (spd->bus_width & 0x7));
	if ((spd->bus_width >> 3) & 0x3)
	pdimm->ec_sdram_width = 8;
	else
	pdimm->ec_sdram_width = 0;
	pdimm->data_width = pdimm->primary_sdram_width
	+ pdimm->ec_sdram_width;
	pdimm->device_width = 1 << ((spd->organization & 0x7) + 2);

	/* These are the types defined by the JEDEC DDR3 SPD spec */
	pdimm->mirrored_dimm = 0;
	pdimm->registered_dimm = 0;
	switch (spd->module_type & DDR3_SPD_MODULETYPE_MASK) {
	case DDR3_SPD_MODULETYPE_RDIMM:
	case DDR3_SPD_MODULETYPE_MINI_RDIMM:
	case DDR3_SPD_MODULETYPE_72B_SO_RDIMM:
	/* Registered/buffered DIMMs */
	pdimm->registered_dimm = 1;
	for (i = 0; i < 16; i += 2) {
	u8 rcw = spd->mod_section.registered.rcw[i/2];
	pdimm->rcw[i] = (rcw >> 0) & 0x0F;
	pdimm->rcw[i+1] = (rcw >> 4) & 0x0F;
	}
	break;

	case DDR3_SPD_MODULETYPE_UDIMM:
	case DDR3_SPD_MODULETYPE_SO_DIMM:
	case DDR3_SPD_MODULETYPE_MICRO_DIMM:
	case DDR3_SPD_MODULETYPE_MINI_UDIMM:
	case DDR3_SPD_MODULETYPE_MINI_CDIMM:
	case DDR3_SPD_MODULETYPE_72B_SO_UDIMM:
	case DDR3_SPD_MODULETYPE_72B_SO_CDIMM:
	case DDR3_SPD_MODULETYPE_LRDIMM:
	case DDR3_SPD_MODULETYPE_16B_SO_DIMM:
	case DDR3_SPD_MODULETYPE_32B_SO_DIMM:
	/* Unbuffered DIMMs */
	if (spd->mod_section.unbuffered.addr_mapping & 0x1)
	pdimm->mirrored_dimm = 1;
	break;

	default:
	printf("unknown module_type 0x%02X\n", spd->module_type);
	return 1;
	}

	/* SDRAM device parameters */
	pdimm->n_row_addr = ((spd->addressing >> 3) & 0x7) + 12;
	pdimm->n_col_addr = (spd->addressing & 0x7) + 9;
	pdimm->n_banks_per_sdram_device = 8 << ((spd->density_banks >> 4) & 0x7);

	/*
	* The SPD spec has not the ECC bit,
	* We consider the DIMM as ECC capability
	* when the extension bus exist
	*/
	if (pdimm->ec_sdram_width)
	pdimm->edc_config = 0x02;
	else
	pdimm->edc_config = 0x00;

	/*
	* The SPD spec has not the burst length byte
	* but DDR3 spec has nature BL8 and BC4,
	* BL8 -bit3, BC4 -bit2
	*/
	pdimm->burst_lengths_bitmask = 0x0c;
	pdimm->row_density = __ilog2(pdimm->rank_density);

	/* MTB - medium timebase
	* The unit in the SPD spec is ns,
	* We convert it to ps.
	* eg: MTB = 0.125ns (125ps)
	*/
	mtb_ps = (spd->mtb_dividend * 1000) /spd->mtb_divisor;
	pdimm->mtb_ps = mtb_ps;

	/*
	* FTB - fine timebase
	* use 1/10th of ps as our unit to avoid floating point
	* eg, 10 for 1ps, 25 for 2.5ps, 50 for 5ps
	*/
	ftb_10th_ps =
	((spd->ftb_div & 0xf0) >> 4) * 10 / (spd->ftb_div & 0x0f);
	pdimm->ftb_10th_ps = ftb_10th_ps;
	/*
	* sdram minimum cycle time
	* we assume the MTB is 0.125ns
	* eg:
	* tck_min=15 MTB (1.875ns) ->DDR3-1066
	* =12 MTB (1.5ns) ->DDR3-1333
	* =10 MTB (1.25ns) ->DDR3-1600
	*/
	pdimm->tckmin_x_ps = spd->tck_min * mtb_ps +
	(spd->fine_tck_min * ftb_10th_ps) / 10;

	/*
	* CAS latency supported
	* bit4 - CL4
	* bit5 - CL5
	* bit18 - CL18
	*/
	pdimm->caslat_x = ((spd->caslat_msb << 8) \| spd->caslat_lsb) << 4;

	/*
	* min CAS latency time
	* eg: taa_min =
	* DDR3-800D 100 MTB (12.5ns)
	* DDR3-1066F 105 MTB (13.125ns)
	* DDR3-1333H 108 MTB (13.5ns)
	* DDR3-1600H 90 MTB (11.25ns)
	*/
	pdimm->taa_ps = spd->taa_min * mtb_ps +
	(spd->fine_taa_min * ftb_10th_ps) / 10;

	/*
	* min write recovery time
	* eg:
	* twr_min = 120 MTB (15ns) -> all speed grades.
	*/
	pdimm->twr_ps = spd->twr_min * mtb_ps;

	/*
	* min RAS to CAS delay time
	* eg: trcd_min =
	* DDR3-800 100 MTB (12.5ns)
	* DDR3-1066F 105 MTB (13.125ns)
	* DDR3-1333H 108 MTB (13.5ns)
	* DDR3-1600H 90 MTB (11.25)
	*/
	pdimm->trcd_ps = spd->trcd_min * mtb_ps +
	(spd->fine_trcd_min * ftb_10th_ps) / 10;

	/*
	* min row active to row active delay time
	* eg: trrd_min =
	* DDR3-800(1KB page) 80 MTB (10ns)
	* DDR3-1333(1KB page) 48 MTB (6ns)
	*/
	pdimm->trrd_ps = spd->trrd_min * mtb_ps;

	/*
	* min row precharge delay time
	* eg: trp_min =
	* DDR3-800D 100 MTB (12.5ns)
	* DDR3-1066F 105 MTB (13.125ns)
	* DDR3-1333H 108 MTB (13.5ns)
	* DDR3-1600H 90 MTB (11.25ns)
	*/
	pdimm->trp_ps = spd->trp_min * mtb_ps +
	(spd->fine_trp_min * ftb_10th_ps) / 10;

	/* min active to precharge delay time
	* eg: tRAS_min =
	* DDR3-800D 300 MTB (37.5ns)
	* DDR3-1066F 300 MTB (37.5ns)
	* DDR3-1333H 288 MTB (36ns)
	* DDR3-1600H 280 MTB (35ns)
	*/
	pdimm->tras_ps = (((spd->tras_trc_ext & 0xf) << 8) \| spd->tras_min_lsb)
	* mtb_ps;
	/*
	* min active to actice/refresh delay time
	* eg: tRC_min =
	* DDR3-800D 400 MTB (50ns)
	* DDR3-1066F 405 MTB (50.625ns)
	* DDR3-1333H 396 MTB (49.5ns)
	* DDR3-1600H 370 MTB (46.25ns)
	*/
	pdimm->trc_ps = (((spd->tras_trc_ext & 0xf0) << 4) \| spd->trc_min_lsb)
	* mtb_ps + (spd->fine_trc_min * ftb_10th_ps) / 10;
	/*
	* min refresh recovery delay time
	* eg: tRFC_min =
	* 512Mb 720 MTB (90ns)
	* 1Gb 880 MTB (110ns)
	* 2Gb 1280 MTB (160ns)
	*/
	pdimm->trfc_ps = ((spd->trfc_min_msb << 8) \| spd->trfc_min_lsb)
	* mtb_ps;
	/*
	* min internal write to read command delay time
	* eg: twtr_min = 40 MTB (7.5ns) - all speed bins.
	* tWRT is at least 4 mclk independent of operating freq.
	*/
	pdimm->twtr_ps = spd->twtr_min * mtb_ps;

	/*
	* min internal read to precharge command delay time
	* eg: trtp_min = 40 MTB (7.5ns) - all speed bins.
	* tRTP is at least 4 mclk independent of operating freq.
	*/
	pdimm->trtp_ps = spd->trtp_min * mtb_ps;

	/*
	* Average periodic refresh interval
	* tREFI = 7.8 us at normal temperature range
	* = 3.9 us at ext temperature range
	*/
	pdimm->refresh_rate_ps = 7800000;
	if ((spd->therm_ref_opt & 0x1) && !(spd->therm_ref_opt & 0x2)) {
	pdimm->refresh_rate_ps = 3900000;
	pdimm->extended_op_srt = 1;
	}

	/*
	* min four active window delay time
	* eg: tfaw_min =
	* DDR3-800(1KB page) 320 MTB (40ns)
	* DDR3-1066(1KB page) 300 MTB (37.5ns)
	* DDR3-1333(1KB page) 240 MTB (30ns)
	* DDR3-1600(1KB page) 240 MTB (30ns)
	*/
	pdimm->tfaw_ps = (((spd->tfaw_msb & 0xf) << 8) \| spd->tfaw_min)
	* mtb_ps;

	return 0;
	}