#!/usr/bin/perl -w
#
# Copyright 1998, 1999 Philip Edelbrock <phil@netroedge.com>
# modified by Christian Zuckschwerdt <zany@triq.net>
# modified by Burkart Lingner <burkart@bollchen.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., 675 Mass Ave, Cambridge, MA 02139, USA.
#
# Version 0.4  1999  Philip Edelbrock <phil@netroedge.com>
# Version 0.5  2000-03-30  Christian Zuckschwerdt <zany@triq.net>
#  html output (selectable by commandline switches)
# Version 0.6  2000-09-16  Christian Zuckschwerdt <zany@triq.net>
#  updated according to SPD Spec Rev 1.2B
#  see http://developer.intel.com/technology/memory/pc133sdram/spec/Spdsd12b.htm
# Version 0.7  2002-11-08  Jean Delvare <khali@linux-fr.org>
#  pass -w and use strict
#  valid HTML 3.2 output (--format mode)
#  miscellaneous formatting enhancements and bug fixes
#  clearer HTML output (original patch by Nick Kurshev <nickols_k@mail.ru>)
#  stop decoding on checksum error by default (--checksum option forces)
# Version 0.8  2005-06-20  Burkart Lingner <burkart@bollchen.de>
#  adapted to Kernel 2.6's /sys filesystem
#
#
# EEPROM data decoding for SDRAM DIMM modules. 
#
# Two assumptions: lm_sensors-2.x installed,
# and Perl is at /usr/bin/perl
#
# use the following command line switches
#  -f, --format            print nice html output
#  -b, --bodyonly          don't print html header
#                          (useful for postprocessing the output)
#  -c, --checksum          decode completely even if checksum fails
#  -h, --help              display this usage summary
#
# References: 
# PC SDRAM Serial Presence 
# Detect (SPD) Specification, Intel, 
# 1997,1999, Rev 1.2B
#
# Jedec Standards 4.1.x & 4.5.x
# http://www.jedec.org
#

use strict;
use vars qw($opt_html $opt_body $opt_bodyonly $opt_igncheck);

sub printl ($$) # print a line w/ label and value
{
   my ($label, $value) = @_;
   if ($opt_html) {
       $label =~ s/</\&lt;/sg;
       $label =~ s/>/\&gt;/sg;
       $label =~ s/\n/<br>\n/sg;
       $value =~ s/</\&lt;/sg;
       $value =~ s/>/\&gt;/sg;
       $value =~ s/\n/<br>\n/sg;
       print "<tr><td valign=top>$label</td><td>$value</td></tr>\n";
   } else {
       $value =~ s%\n%\n\t\t%sg;
       print "$label\t$value\n";
   }
}

sub printl2 ($$) # print a line w/ label and value (outside a table)
{
   my ($label, $value) = @_;
   if ($opt_html) {
       $label =~ s/</\&lt;/sg;
       $label =~ s/>/\&gt;/sg;
       $label =~ s/\n/<br>\n/sg;
       $value =~ s/</\&lt;/sg;
       $value =~ s/>/\&gt;/sg;
       $value =~ s/\n/<br>\n/sg;
       print "$label: $value\n";
   } else {
       $value =~ s%\n%\n\t\t%sg;
       print "$label\t$value\n";
   }
}

sub prints ($) # print seperator w/ given text
{
   my ($label) = @_;
   if ($opt_html) {
       $label =~ s/</\&lt;/sg;
       $label =~ s/>/\&gt;/sg;
       $label =~ s/\n/<br>\n/sg;
       print "<tr><td align=center colspan=2><b>$label</b></td></tr>\n";
   } else {
       print "\n---=== $label ===---\n";
   }
}

sub printh ($) # print header w/ given text
{
   my ($label) = @_;
   if ($opt_html) {
       $label =~ s/</\&lt;/sg;
       $label =~ s/>/\&gt;/sg;
       $label =~ s/\n/<br>\n/sg;
       print "<h1>$label</h1>\n";
   } else {
	print "\n$label\n";
   }
}

sub readspd16 ($$) { # reads 16 bytes from SPD-EEPROM
	my ($offset, $dimm_i) = @_;
	if (-e "/sys/bus/i2c/drivers/eeprom") {
		# Kernel 2.6 with sysfs
		open (HANDLE, "/sys/bus/i2c/drivers/eeprom/$dimm_i/eeprom");
		binmode HANDLE;
		seek (HANDLE, $offset, 0);
		read (HANDLE, my $eeprom, 16);
		close HANDLE;
		my @bytes = ();
		for my $i ( 0 .. 15 ) {
			$_ = ord substr($eeprom, $i, 1);
			push(@bytes, $_);
		}
		return @bytes;
	} else {
		# Kernel 2.4 with procfs
		if ($offset == 0) {		# bytes 0..15
			$_=`cat /proc/sys/dev/sensors/$dimm_i/00`;
		} elsif ($offset == 16) {	# bytes 16..31
			$_=`cat /proc/sys/dev/sensors/$dimm_i/10`;
		} elsif ($offset == 32) {	# bytes 32..47
			$_=`cat /proc/sys/dev/sensors/$dimm_i/20`;
		} elsif ($offset == 48) {	# bytes 48..63
			$_=`cat /proc/sys/dev/sensors/$dimm_i/30`;
		} elsif ($offset == 64) {	# bytes 64..79
			$_=`cat /proc/sys/dev/sensors/$dimm_i/40`;
		} elsif ($offset == 80) {	# bytes 80..95
			$_=`cat /proc/sys/dev/sensors/$dimm_i/50`;
		} elsif ($offset == 96) {	# bytes 96..111
			$_=`cat /proc/sys/dev/sensors/$dimm_i/60`;
		} elsif ($offset == 112) {	# bytes 112..127
			$_=`cat /proc/sys/dev/sensors/$dimm_i/70`;
		} else {			# illegal offset
			$_='255 'x15 . '255';
		}
		return split(" ");
	}
}

for (@ARGV) {
    if (/-h/) {
		print "Usage: $0 [-f|-b|-h]\n\n",
			"  -f, --format            print nice html output\n",
			"  -b, --bodyonly          don't print html header\n",
			"                          (useful for postprocessing the output)\n",
			"  -c, --checksum          decode completely even if checksum fails\n",
			"  -h, --help              display this usage summary\n";
		exit;
    }
    $opt_html = 1 if (/-f/);
    $opt_bodyonly = 1 if (/-b/);
    $opt_igncheck = 1 if (/-c/);
}
$opt_body = $opt_html && ! $opt_bodyonly;

if ($opt_body)
{
	print "<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 3.2 Final//EN\">\n",
	      "<html><head>\n",
		  "\t<meta HTTP-EQUIV=\"Content-Type\" CONTENT=\"text/html; charset=iso-8859-1\">\n",
		  "\t<title>PC DIMM Serial Presence Detect Tester/Decoder Output</title>\n",
		  "</head><body>\n";
}

printh '
PC DIMM Serial Presence Detect Tester/Decoder
By Philip Edelbrock, Christian Zuckschwerdt, Burkart Lingner and others
Version 2.6.6
';

my $dimm_count=0;
if (-e "/sys/bus/i2c/drivers/eeprom") { $_=`ls /sys/bus/i2c/drivers/eeprom`; }
else { $_=`ls /proc/sys/dev/sensors/`; }
my @dimm_list=split();

for my $i ( 0 .. $#dimm_list ) {
	$_=$dimm_list[$i];
	if (-e "/sys/bus/i2c/drivers/eeprom" || /^eeprom-/) {
		my $dimm_checksum=0;
		$dimm_count += 1;

		print "<b><u><br><br>" if $opt_html;
		if (-e "/sys/bus/i2c/drivers/eeprom") {
			printl2 "Decoding EEPROM" , " /sys/bus/i2c/drivers/eeprom/$dimm_list[$i]";
		} else {
			printl2 "Decoding EEPROM" , " /proc/sys/dev/sensors/$dimm_list[$i]";
		}
		print "</u></b>" if $opt_html;
		print "<table border=1>\n" if $opt_html;
		if (-e "/sys/bus/i2c/drivers/eeprom") {
			if (/^[^-]+-([^-]+)$/) {
				my $dimm_num=$1 - 49;
				printl "Guessing DIMM is in", "bank $dimm_num";
			}
		} else {
			if (/^[^-]+-[^-]+-[^-]+-([^-]+)$/) {
				my $dimm_num=$1 - 49;
				printl "Guessing DIMM is in", "bank $dimm_num";
			}
		}
# Decode first 16 bytes
		prints "The Following is Required Data and is Applicable to all DIMM Types";

		my @bytes = readspd16 (0, $dimm_list[$i]);

		for my $j ( 0 .. 15 ) { $dimm_checksum = $dimm_checksum + $bytes[$j];  }

		printl "# of bytes written to SDRAM EEPROM",$bytes[0];

		my $l = "Total number of bytes in EEPROM";
		if ($bytes[1] <= 13) {
			printl $l, 2**$bytes[1];
		} elsif ($bytes[1] == 0) {
			printl $l, "RFU"; 
		} else { printl $l, "ERROR!"; }

		$l = "Fundamental Memory type";
		if ($bytes[2] == 2) { printl $l, "EDO"; }
		elsif ($bytes[2] == 4) { printl $l, "SDR SDRAM"; }
		elsif ($bytes[2] == 7) { printl $l, "DDR SDRAM"; }
		elsif ($bytes[2] == 17) { printl $l, "Rambus [UNSUPPORTED]"; }
		elsif ($bytes[2] == 1) { printl $l, "Direct Rambus [UNSUPPORTED]"; }
		else { printl $l, "???"; }

		$l = "Number of Row Address Bits (SDRAM only)";
		if ($bytes[3] == 0) { printl $l, "Undefined!" } 		
		elsif ($bytes[3] == 1) { printl $l, "1/16" } 		
		elsif ($bytes[3] == 2) { printl $l, "2/17" } 		
		elsif ($bytes[3] == 3) { printl $l, "3/18" }
		else { printl $l, $bytes[3]; }

		$l = "Number of Col Address Bits (SDRAM only)";
		if ($bytes[4] == 0) { printl $l, "Undefined!" } 		
		elsif ($bytes[4] == 1) { printl $l, "1/16" } 		
		elsif ($bytes[4] == 2) { printl $l, "2/17" } 		
		elsif ($bytes[4] == 3) { printl $l, "3/18" }
		else { printl $l, $bytes[4]; }

		$l = "Number of Module Rows";
		if ($bytes[5] == 0 ) { printl $l, "Undefined!"; }
		else { printl $l, $bytes[5]; }

		$l = "Data Width (SDRAM only)";
		if ($bytes[7] > 1) { printl $l, "Undefined!" } else {
			my $temp=($bytes[7]*256) + $bytes[6];
			printl $l, $temp;
		}

		$l = "Module Interface Signal Levels";
		if ($bytes[8] == 0) { printl $l, "5.0 Volt/TTL";}
		elsif ($bytes[8] == 1) { printl $l, "LVTTL";}
		elsif ($bytes[8] == 2) { printl $l, "HSTL 1.5";}
		elsif ($bytes[8] == 3) { printl $l, "SSTL 3.3";}
		elsif ($bytes[8] == 4) { printl $l, "SSTL 2.5";}
		elsif ($bytes[8] == 255) { printl $l, "New Table";}
		else { printl $l, "Undefined!";}

		$l = "Cycle Time (SDRAM) highest CAS latency";
		my $temp=($bytes[9] >> 4) + ($bytes[9] & 0xf) * 0.1;
		printl $l, "${temp}ns";

		$l = "Access Time (SDRAM)";
		$temp=($bytes[10] >> 4) + ($bytes[10] & 0xf) * 0.1;
		printl $l, "${temp}ns";

		$l = "Module Configuration Type";
		if ($bytes[11] == 0) { printl $l, "No Parity"; }
		elsif ($bytes[11] == 1) { printl $l, "Parity"; }
		elsif ($bytes[11] == 2) { printl $l, "ECC"; }
		else { printl $l, "Undefined!"; }

		$l = "Refresh Type";
		if ($bytes[12] > 126) { printl $l, "Self Refreshing"; }
		else { printl $l, "Not Self Refreshing"; }

		$l = "Refresh Rate";
		$temp=$bytes[12] & 0x7f;
		if ($temp == 0) { printl $l, "Normal (15.625uS)"; }
		elsif ($temp == 1) { printl $l, "Reduced (3.9uS)"; }
		elsif ($temp == 2) { printl $l, "Reduced (7.8uS)"; }
		elsif ($temp == 3) { printl $l, "Extended (31.3uS)"; }
		elsif ($temp == 4) { printl $l, "Extended (62.5uS)"; }
		elsif ($temp == 5) { printl $l, "Extended (125uS)"; }
		else { printl $l, "Undefined!";}

		$l = "Primary SDRAM Component Bank Config";
		if ($bytes[13]>126) { printl $l, "Bank2 = 2 x Bank1";}
		else { printl $l, "No Bank2 OR Bank2 = Bank1 width";}

		$l = "Primary SDRAM Component Widths";
		$temp=$bytes[13] & 0x7f;
		if ($temp == 0) { printl $l, "Undefined!\n"; }
		else { printl $l, $temp; }

		$l = "Error Checking SDRAM Component Bank Config";
		if ($bytes[14]>126) { printl $l, "Bank2 = 2 x Bank1";}
		else { printl $l, "No Bank2 OR Bank2 = Bank1 width";}

		$l = "Error Checking SDRAM Component Widths";
		$temp=$bytes[14] & 0x7f;
		if ($temp == 0) { printl $l, "Undefined!"; }
		else { printl $l, $temp; }

		$l = "Min Clock Delay for Back to Back Random Access";
		if ($bytes[15] == 0) { printl $l, "Undefined!"; }
		else { printl $l, $bytes[15]; }

		prints "The Following Apply to SDRAM DIMMs ONLY";

# Decode next 16 bytes
		@bytes = readspd16 (16, $dimm_list[$i]);
		for my $j ( 0 .. 15 ) { $dimm_checksum = $dimm_checksum + $bytes[$j]; }

		$l = "Burst lengths supported";
		$temp="";
		if (($bytes[0] & 1) > 0) { $temp .= "Burst Length = 1\n"; }
		if (($bytes[0] & 2) > 0) { $temp .= "Burst Length = 2\n"; }
		if (($bytes[0] & 4) > 0) { $temp .= "Burst Length = 4\n"; }
		if (($bytes[0] & 8) > 0) { $temp .= "Burst Length = 8\n"; }
		if (($bytes[0] & 16) > 0) { $temp .= "Undefined! (bit 4)\n"; }
		if (($bytes[0] & 32) > 0) { $temp .= "Undefined! (bit 5)\n"; }
		if (($bytes[0] & 64) > 0) { $temp .= "Undefined! (bit 6)\n"; }
		if (($bytes[0] & 128) > 0) { $temp .= "Burst Length = Page\n"; }
		if ($bytes[0] == 0) { $temp .= "(None Supported)\n";}
		printl $l, $temp;

		$l = "Number of Device Banks";
		if ($bytes[1] == 0) { printl $l, "Undefined/Reserved!"; }
		else { printl $l, $bytes[1]; }

		$l = "Supported CAS Latencies";
		$temp="";
		if (($bytes[2] & 1) > 0) { $temp .= "CAS Latency = 1\n";}
		if (($bytes[2] & 2) > 0) { $temp .= "CAS Latency = 2\n"; }
		if (($bytes[2] & 4) > 0) { $temp .= "CAS Latency = 3\n"; }
		if (($bytes[2] & 8) > 0) { $temp .= "CAS Latency = 4\n"; }
		if (($bytes[2] & 16) > 0) { $temp .= "CAS Latency = 5\n"; }
		if (($bytes[2] & 32) > 0) { $temp .= "CAS Latency = 6\n"; }
		if (($bytes[2] & 64) > 0) { $temp .= "CAS Latency = 7\n"; }
		if (($bytes[2] & 128) > 0) { $temp .= "Undefined (bit 7)\n"; }
		if ($bytes[2] == 0) { $temp .= "(None Supported)\n";}
		printl $l, $temp;

		$l = "Supported CS Latencies";
		$temp="";
		if (($bytes[3] & 1) > 0) { $temp .= "CS Latency = 0\n";}
		if (($bytes[3] & 2) > 0) { $temp .= "CS Latency = 1\n"; }
		if (($bytes[3] & 4) > 0) { $temp .= "CS Latency = 2\n"; }
		if (($bytes[3] & 8) > 0) { $temp .= "CS Latency = 3\n"; }
		if (($bytes[3] & 16) > 0) { $temp .= "CS Latency = 4\n"; }
		if (($bytes[3] & 32) > 0) { $temp .= "CS Latency = 5\n"; }
		if (($bytes[3] & 64) > 0) { $temp .= "CS Latency = 6\n"; }
		if (($bytes[3] & 128) > 0) { $temp .= "Undefined (bit 7)\n"; }
		if ($bytes[3] == 0) { $temp .= "(None Supported)\n";}
		printl $l, $temp;

		$l = "Supported WE Latencies";
		$temp="";
		if (($bytes[4] & 1) > 0) { $temp .= "WE Latency = 0\n";}
		if (($bytes[4] & 2) > 0) { $temp .= "WE Latency = 1\n"; }
		if (($bytes[4] & 4) > 0) { $temp .= "WE Latency = 2\n"; }
		if (($bytes[4] & 8) > 0) { $temp .= "WE Latency = 3\n"; }
		if (($bytes[4] & 16) > 0) { $temp .= "WE Latency = 4\n"; }
		if (($bytes[4] & 32) > 0) { $temp .= "WE Latency = 5\n"; }
		if (($bytes[4] & 64) > 0) { $temp .= "WE Latency = 6\n"; }
		if (($bytes[4] & 128) > 0) { $temp .= "Undefined (bit 7)\n"; }
		if ($bytes[4] == 0) { $temp .= "(None Supported)\n";}
		printl $l, $temp;

		$l = "SDRAM Module Attributes";
		$temp="";
		if (($bytes[5] & 1) > 0) { $temp .= "Buffered Address/Control Inputs\n";}
		if (($bytes[5] & 2) > 0) { $temp .= "Registered Address/Control Inputs\n"; }
		if (($bytes[5] & 4) > 0) { $temp .= "On card PLL (clock)\n"; }
		if (($bytes[5] & 8) > 0) { $temp .= "Buffered DQMB Inputs\n"; }
		if (($bytes[5] & 16) > 0) { $temp .= "Registered DQMB Inputs\n"; }
		if (($bytes[5] & 32) > 0) { $temp .= "Differential Clock Input\n"; }
		if (($bytes[5] & 64) > 0) { $temp .= "Redundant Row Address\n"; }
		if (($bytes[5] & 128) > 0) { $temp .= "Undefined (bit 7)\n"; }
		if ($bytes[5] == 0) { $temp .= "(None Reported)\n";}
		printl $l, $temp;

		$l = "SDRAM Device Attributes (General)";
		$temp="";
		if (($bytes[6] & 1) > 0) { $temp .= "Supports Early RAS# Recharge\n";}
		if (($bytes[6] & 2) > 0) { $temp .= "Supports Auto-Precharge\n"; }
		if (($bytes[6] & 4) > 0) { $temp .= "Supports Precharge All\n"; }
		if (($bytes[6] & 8) > 0) { $temp .= "Supports Write1/Read Burst\n"; }
		if (($bytes[6] & 16) > 0) { $temp .= "Lower VCC Tolerance:5%\n"; }
		if (($bytes[6] & 16) == 0) { $temp .= "Lower VCC Tolerance:10%\n"; }
		if (($bytes[6] & 32) > 0) { $temp .= "Upper VCC Tolerance:5%\n"; }
		if (($bytes[6] & 32) == 0) { $temp .= "Upper VCC Tolerance:10%\n"; }
		if (($bytes[6] & 64) > 0) { $temp .= "Undefined (bit 6)\n"; }
		if (($bytes[6] & 128) > 0) { $temp .= "Undefined (bit 7)\n"; }
		printl $l, $temp;

		$l = "SDRAM Cycle Time (2nd highest CAS)";
		$temp = $bytes[7] >> 4;
		if ($temp == 0) { printl $l, "Undefined!"; }
		else {
			if ($temp < 4 ) {$temp=$temp + 15;}
			printl $l, $temp + (($bytes[7] & 0xf) * 0.1) . "nS";
		}

		$l = "SDRAM Access from Clock Time (2nd highest CAS)";
		$temp = $bytes[8] >> 4;
		if ($temp == 0) { printl $l, "Undefined!"; }
		else {
			if ($temp < 4 ) {$temp=$temp + 15;}
			printl $l, $temp + (($bytes[8] & 0xf) * 0.1) . "nS";
		}

		prints "The Following are Optional (may be Bogus)";

		$l = "SDRAM Cycle Time (3rd highest CAS)";
		$temp = $bytes[9] >> 2;
		if ($temp == 0) { printl $l, "Undefined!"; }
		else { printl $l, $temp + ($bytes[9] & 0x3) * 0.25 . "nS"; }

		$l = "SDRAM Access from Clock Time (3rd highest CAS)";
		$temp = $bytes[10] >> 2;
		if ($temp == 0) { printl $l, "Undefined!"; }
		else { printl $l, $temp + ($bytes[10] & 0x3) * 0.25 . "nS"; }

		prints "The Following are Required (for SDRAMs)";

		$l = "Minumum Row Precharge Time";
		if ($bytes[11] == 0) { printl $l, "Undefined!"; }
		else { printl $l, "$bytes[11]nS"; }

		$l = "Row Active to Row Active Min";
		if ($bytes[12] == 0) { printl $l, "Undefined!"; }
		else { printl $l, "$bytes[12]nS"; }

		$l = "RAS to CAS Delay";
		if ($bytes[13] == 0) { printl $l, "Undefined!"; }
		else { printl $l, "$bytes[13]nS"; }

		$l = "Min RAS Pulse Width";
		if ($bytes[14] == 0) { printl $l, "Undefined!"; }
		else { printl $l, "$bytes[14]nS"; }


		prints "The Following are Required and Apply to ALL DIMMs";

		$l = "Row Densities";
		$temp="";
		if (($bytes[15] & 1) > 0) { $temp .= "4 MByte\n";}
		if (($bytes[15] & 2) > 0) { $temp .= "8 MByte\n"; }
		if (($bytes[15] & 4) > 0) { $temp .= "16 MByte\n"; }
		if (($bytes[15] & 8) > 0) { $temp .= "32 MByte\n"; }
		if (($bytes[15] & 16) > 0) { $temp .= "64 MByte\n"; }
		if (($bytes[15] & 32) > 0) { $temp .= "128 MByte\n"; }
		if (($bytes[15] & 64) > 0) { $temp .= "256 MByte\n"; }
		if (($bytes[15] & 128) > 0) { $temp .= "512 MByte\n"; }
		if ($bytes[15] == 0) { $temp .= "(Undefined! -- None Reported!)\n";}
		printl $l, $temp;


# Decode next 16 bytes (32-47)
		@bytes = readspd16 (32, $dimm_list[$i]);

		for my $j ( 0 .. 15 ) { $dimm_checksum = $dimm_checksum + $bytes[$j];  }

		prints "The Following are Proposed and Apply to SDRAM DIMMs";

		$l = "Command and Address Signal Setup Time";
		$temp = (($bytes[0] & 0x7f) >> 4) + ($bytes[0] & 0xf) * 0.1;
		printl $l, ( ($bytes[0] >> 7) ? -$temp : $temp ) . "nS";

		$l = "Command and Address Signal Hold Time";
		$temp = (($bytes[1] & 0x7f) >> 4) + ($bytes[1] & 0xf) * 0.1;
		printl $l, ( ($bytes[1] >> 7) ? -$temp : $temp ) . "nS";

		$l = "Data Signal Setup Time";
		$temp =(($bytes[2] & 0x7f) >> 4) + ($bytes[2] & 0xf) * 0.1;
		printl $l, ( ($bytes[2] >> 7) ? -$temp : $temp ) . "nS";

		$l = "Data Signal Hold Time";
		$temp = (($bytes[3] & 0x7f) >> 4) + ($bytes[3] & 0xf) * 0.1;
		printl $l, ( ($bytes[3] >> 7) ? -$temp : $temp ) . "nS";

# That's it for the lower part of an SDRAM EEPROM's memory!
# Decode next 16 bytes (48-63)
		@bytes = readspd16 (48, $dimm_list[$i]);

		for my $j ( 0 .. 14 ) { $dimm_checksum = $dimm_checksum + $bytes[$j];  }

		printl "SPD Revision code ", sprintf("%x", $bytes[14]);
		$l = "EEPROM Checksum of bytes 0-62";
		$dimm_checksum &= 0xff;
		printl $l, ($bytes[15]==$dimm_checksum?
			sprintf("OK (0x%.2X)",$bytes[15]):
			sprintf("Bad (found 0x%.2X, calculated 0x%.2X)\n",$bytes[15],$dimm_checksum));

		if($bytes[15]==$dimm_checksum || $opt_igncheck) {
# Decode next 16 bytes (64-79)
		@bytes = readspd16 (64, $dimm_list[$i]);

		$l = "Manufacturer's JEDEC ID Code";
		$temp = sprintf("0x%.2X%.2X%.2X%.2X%.2X%.2X%.2X%.2X\n",$bytes[0],$bytes[1],$bytes[2],$bytes[3],$bytes[4],$bytes[5],$bytes[6],$bytes[7]);
		printl $l, $temp;
		$temp = pack("c8",
			$bytes[0],$bytes[1],$bytes[2],$bytes[3],$bytes[4],$bytes[5],$bytes[6],$bytes[7]);
		printl $l, "(\"$temp\")";

		$l = "Manufacturing Location Code";
		$temp = sprintf("0x%.2X\n",$bytes[8]);
		printl $l, $temp;

		$l = "Manufacurer's Part Number";
# Decode next 16 bytes (80-95)
		my @bytes2= readspd16 (80, $dimm_list[$i]);

		$temp = pack("c18",$bytes[9],$bytes[10],$bytes[11],$bytes[12],$bytes[13],$bytes[14],$bytes[15],
			$bytes2[0],$bytes2[1],$bytes2[2],$bytes2[3],$bytes2[4],$bytes2[5],$bytes2[6],$bytes2[7],$bytes2[8],$bytes2[9],$bytes2[10]);
		printl $l, $temp;

		$l = "Revision Code";
		$temp = sprintf("0x%.2X%.2X\n",$bytes2[11],$bytes2[12]);
		printl $l, $temp;

		$l = "Manufacturing Date";
		$temp = sprintf("0x%.2X%.2X\n",$bytes2[13],$bytes2[14]);
		printl $l, $temp;

		$l = "Assembly Serial Number";
# Decode next 16 bytes (96-111)
		@bytes = readspd16 (96, $dimm_list[$i]);

		$temp = sprintf("0x%.2X%.2X%.2X%.2X\n",$bytes2[15],$bytes[0],$bytes[1],$bytes[2]);
# Decode next 16 bytes (112-127)
		@bytes = readspd16 (112, $dimm_list[$i]);

		$l = "Intel Specification for Frequency";
		if ($bytes[14] == 102) { printl $l, "66MHz\n"; }
		elsif ($bytes[14] == 100) { printl $l, "100MHz\n"; }
		else { printl $l, "Undefined!\n"; }

		$l = "Intel Spec Details for 100MHz Support";
		$temp="";
		if (($bytes[15] & 1) > 0) { $temp .= "Intel Concurrent AutoPrecharge\n";}
		if (($bytes[15] & 2) > 0) { $temp .= "CAS Latency = 2\n";}
		if (($bytes[15] & 4) > 0) { $temp .= "CAS Latency = 3\n";}
		if (($bytes[15] & 8) > 0) { $temp .= "Junction Temp A (90 degrees C)\n";}
		if (($bytes[15] & 8) == 0) { $temp .= "Junction Temp B (100 degrees C)\n";}
		if (($bytes[15] & 16) > 0) { $temp .= "CLK 3 Connected\n";}
		if (($bytes[15] & 32) > 0) { $temp .= "CLK 2 Connected\n";}
		if (($bytes[15] & 64) > 0) { $temp .= "CLK 1 Connected\n";}
		if (($bytes[15] & 128) > 0) { $temp .= "CLK 0 Connected\n";}
		if ($bytes[15] > 175) { $temp .= "Double Sided DIMM\n"; }
		else { $temp .= "Single Sided DIMM\n";}
		printl $l, $temp;
		}

		print "</table>\n" if $opt_html;
	}
}
print '<br><br>' if $opt_html;
printl2 "Number of SDRAM DIMMs detected and decoded", $dimm_count;

print "</body></html>\n" if $opt_body;
print "\nTry '$0 --format' for html output.\n" unless $opt_html;