Print only the DDR2 timings which were properly defined.
---
eeprom/decode-dimms | 62 ++++++++++++++++++++++++++++++++++-----------------
1 file changed, 42 insertions(+), 20 deletions(-)
--- i2c-tools.orig/eeprom/decode-dimms 2012-10-22 09:50:20.000000000 +0200
+++ i2c-tools/eeprom/decode-dimms 2012-10-22 10:22:53.744716447 +0200
@@ -1194,29 +1194,51 @@ sub decode_ddr2_sdram($)
# more timing information
prints("Timing Parameters");
- printl("Address/Command Setup Time Before Clock (tIS)",
- tns(ddr2_sdram_atime($bytes->[32])));
- printl("Address/Command Hold Time After Clock (tIH)",
- tns(ddr2_sdram_atime($bytes->[33])));
- printl("Data Input Setup Time Before Strobe (tDS)",
- tns(ddr2_sdram_atime($bytes->[34])));
- printl("Data Input Hold Time After Strobe (tDH)",
- tns(ddr2_sdram_atime($bytes->[35])));
+ # According to the JEDEC standard, the four timings below can't be less
+ # than 0.1 ns, however we've seen memory modules code such values so
+ # handle them properly.
+ printl_cond($bytes->[32] && $bytes->[32] != 0xff,
+ "Address/Command Setup Time Before Clock (tIS)",
+ tns(ddr2_sdram_atime($bytes->[32])));
+ printl_cond($bytes->[33] && $bytes->[33] != 0xff,
+ "Address/Command Hold Time After Clock (tIH)",
+ tns(ddr2_sdram_atime($bytes->[33])));
+ printl_cond($bytes->[34] && $bytes->[34] != 0xff,
+ "Data Input Setup Time Before Strobe (tDS)",
+ tns(ddr2_sdram_atime($bytes->[34])));
+ printl_cond($bytes->[35] && $bytes->[35] != 0xff,
+ "Data Input Hold Time After Strobe (tDH)",
+ tns(ddr2_sdram_atime($bytes->[35])));
+
printl("Minimum Row Precharge Delay (tRP)", tns($trp));
- printl("Minimum Row Active to Row Active Delay (tRRD)",
- tns($bytes->[28]/4));
+ printl_cond($bytes->[28] & 0xfc,
+ "Minimum Row Active to Row Active Delay (tRRD)",
+ tns($bytes->[28]/4));
printl("Minimum RAS# to CAS# Delay (tRCD)", tns($trcd));
printl("Minimum RAS# Pulse Width (tRAS)", tns($tras));
- printl("Write Recovery Time (tWR)", tns($bytes->[36]/4));
- printl("Minimum Write to Read CMD Delay (tWTR)", tns($bytes->[37]/4));
- printl("Minimum Read to Pre-charge CMD Delay (tRTP)",
tns($bytes->[38]/4));
- printl("Minimum Active to Auto-refresh Delay (tRC)",
- tns(ddr2_sdram_rtime($bytes->[41], 0, ($bytes->[40] >> 4) & 7)));
- printl("Minimum Recovery Delay (tRFC)",
- tns(ddr2_sdram_rtime($bytes->[42], $bytes->[40] & 1,
- ($bytes->[40] >> 1) & 7)));
- printl("Maximum DQS to DQ Skew (tDQSQ)", tns($bytes->[44]/100));
- printl("Maximum Read Data Hold Skew (tQHS)", tns($bytes->[45]/100));
+ printl_cond($bytes->[36] & 0xfc,
+ "Write Recovery Time (tWR)",
+ tns($bytes->[36]/4));
+ printl_cond($bytes->[37] & 0xfc,
+ "Minimum Write to Read CMD Delay (tWTR)",
+ tns($bytes->[37]/4));
+ printl_cond($bytes->[38] & 0xfc,
+ "Minimum Read to Pre-charge CMD Delay (tRTP)",
+ tns($bytes->[38]/4));
+
+ printl_cond($bytes->[41] && $bytes->[41] != 0xff,
+ "Minimum Active to Auto-refresh Delay (tRC)",
+ tns(ddr2_sdram_rtime($bytes->[41], 0,
+ ($bytes->[40] >> 4) & 7)));
+ printl_cond($bytes->[42],
+ "Minimum Recovery Delay (tRFC)",
+ tns(ddr2_sdram_rtime($bytes->[42], $bytes->[40] & 1,
+ ($bytes->[40] >> 1) & 7)));
+
+ printl_cond($bytes->[44], "Maximum DQS to DQ Skew (tDQSQ)",
+ tns($bytes->[44]/100));
+ printl_cond($bytes->[45], "Maximum Read Data Hold Skew (tQHS)",
+ tns($bytes->[45]/100));
printl_cond($bytes->[46], "PLL Relock Time", $bytes->[46] . " us");
}
--
Jean Delvare
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