DDR Memory Analysis. Part 1: Kingmax DDR-466
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We proceed with the series of articles devoted to the low level analysis of
the most important characteristics of memory modules using the RightMark
Memory Analyzer test package. The object of our next analysis
is a couple of colored Kingmax DDR-466 modules of the high-performance
hardcore series with stylish original design.
Manufacturer Information
Module manufacturer: Kingmax Inc.
Chip manufacturer: Kingmax Inc.
Web site of the module manufacturer: http://www.kingmax.com/product/color.htm
Web site of the chip manufacturer: N/A
Module Appearance
Photo of the memory module
Photo of the memory chip
Part Numbering System of Modules and Chips
Module Part Number Expansion
Data sheet on Kingmax DDR-466 does not contain information about the expansion of some part numbers of the modules. The documentation provides only brief technical characteristics pertaining to some part numbers. The characteristics of the module under review are provided below.
| Field |
Value |
Expansion |
| 0 |
MPYB62D-38KS4G |
Module density: 256 Mb
Configuration: 32M x64
Module bandwidth: 3.7 GB/sec
Memory clock: 4.3 ns
Data rate: 466 MT/s
Timings (tCL-tRCD-tRP): 3.0-4-4
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SPD module chip data
Description of the SPD general standard:
JEDEC Standard No. 21-C, 4.1.2 - SERIAL PRESENCE DETECT STANDARD, General Standard
Description of the SPD specific standard for DDR:
JEDEC Standard No. 21-C, 4.1.2.4 – Appendix D, Rev. 1.0: SPD’s for DDR SDRAM
| Function |
Byte |
Value |
Expansion |
| Fundamental Memory Type |
2 |
07h |
DDR SDRAM |
| Number of Row Addresses on this assembly |
3 |
0Dh |
13 (RA0-RA12) |
| Number of Column Addresses on this assembly |
4 |
0Ah |
10 (CA0-CA9) |
| Number of DIMM Banks |
5 |
01h |
1 physical bank |
| Data Width of this assembly |
6, 7 |
40h, 00h |
64 bit |
| Voltage Interface Level of this assembly |
8 |
04h |
SSTL 2.5V |
| SDRAM Cycle time (tCK) at maximum supported
CAS# latency (CL X) |
9 |
43h |
4.3 ns (232.5 MHz) |
| DIMM configuration type |
11 |
00h |
Non-ECC |
| Refresh Rate/Type |
12 |
82h |
7.8125 ms – 0.5x reduced self-refresh |
| Primary SDRAM Width (organization type) of the
memory module chips |
13 |
08h |
x8 |
| Error Checking SDRAM Width (organization type)
of the memory chips in the ECC module |
14 |
00h |
Not defined |
| Burst Lengths Supported (BL) |
16 |
0Eh |
BL = 2, 4, 8 |
| Number of Banks on SDRAM Device |
17 |
04h |
4 |
| CAS Latency (CL) |
18 |
18h |
CL = 2.5, 3.0 |
| Minimum clock cycle (tCK) at reduced
CAS latency (CL X-0.5) |
23 |
50h |
5.00 ns (200.0 MHz) |
| Minimum clock cycle (tCK) at reduced
CAS latency (CL X-1.0) |
25 |
00h |
Not defined |
| Minimum Row Precharge Time (tRP) |
27 |
48h |
18.0 ns
4.19, CL = 3.0
3.60, CL = 2.5 |
| Minimum Row Active to Row Active delay (tRRD) |
28 |
28h |
10.0 ns
2.33, CL = 3.0
2.00, CL = 2.5 |
| Minimum RAS to CAS delay (tRCD) |
29 |
48h |
18.0 ns
4.19, CL = 3.0
3.60, CL = 2.5 |
| Minimum Active to Precharge Time (tRAS) |
30 |
28h |
40.0 ns
9.30, CL = 3.0
8.00, CL = 2.5 |
| Module Bank Density |
31 |
40h |
256 MB |
| Minimum Active to Active/Refresh Time (tRC) |
41 |
3Ch |
60.0 ns
13.95, CL = 3.0
12.00, CL = 2.5 |
| Minimum Refresh to Active/Refresh Command Period
(tRFC) |
42 |
46h |
70.0 ns
16.28, CL = 3.0
14.00, CL = 2.5 |
| Maximum device cycle time (tCKmax) |
43 |
30h |
12.0 ns |
| SPD Revision |
62 |
00h |
Revision 0.0 |
| Checksum for Bytes 0-62 |
63 |
AFh |
175 (true) |
| Manufacturer’s JEDEC ID Code (only the first
significant bytes are shown) |
64-71 |
7Fh, 7Fh,
7Fh, 25h |
Kingmax Semiconductor |
| Module Part Number |
73-90 |
- |
MPYB62D-38KS4G-MAAR |
| Module Manufacturing Date |
93-94 |
04h, 00h |
2004 |
| Module Serial Number |
95-98 |
00h, 00h,
00h, 00h |
Not defined |
SPD chip contents look not quite standard. Supported CAS# Latency values – 3.0 and 3.0. The first value (CL X = 3.0) corresponds to the non-standard cycle time – 4.3 ns (nevertheless, it matches the value claimed in Kingmax specification), that is the module operates at about 233 MHz (DDR-466). Timing scheme for this case can be expressed as 3.0-4.2-4.2-9.3, in reality (taking into account that tRCD, tRP and tRAS cannot take non-integral values) – 3.0-4-4-9 (which again matches the values provided above in the part number expansion). The second value of CAS# latency (CL X-0.5 = 2.5) corresponds to the standard (for DDR-400) cycle time of 5.0 ns. Timing scheme in the second case is written as 2.5-3.6-3.6-8 (in reality – 2.5-4-4-8).
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