JEDEC Standard No. 308-U0-RCC
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DDR5 UDIMM Raw Card Annex C
Contents
Page
1 Scope ................................................................................................................................................. 1
2 DDR5 Small Outline DIMM Design File ......................................................................................... 1
3 Module Configuration ....................................................................................................................... 1
4 SDRAM Configuration ..................................................................................................................... 2
5 Supported Speeds .............................................................................................................................. 2
6 Design Deviations ............................................................................................................................. 2
7 General Layout .................................................................................................................................. 3
8 Functional Block Diagram ................................................................................................................ 4
9 SMBus Net Structure ........................................................................................................................ 5
10 Clock Input Net Structure ................................................................................................................. 6
11 Address and Command Net Structure Routing ................................................................................. 7
12 Control Net Structure Routing .......................................................................................................... 8
13 Data Net Structure Routing ............................................................................................................... 9
14 DIMM Impedance Profile ............................................................................................................... 10
15 ALERT_n and RESET_n Net Structure Routing ............................................................................ 11
16 Loading and Test Points .................................................................................................................. 12
17 Cross Section Recommendations .................................................................................................... 13
Tables
Table 1 — DDR5 UDIMM Design File ........................................................................................................ 1
Table 2 — Module Configuration ................................................................................................................. 1
Table 3 — SDRAM Configuration ............................................................................................................... 2
Table 4 — Supported Speeds ........................................................................................................................ 2
Table 5 — Design Deviations ....................................................................................................................... 2
Table 6 — Trace Lengths for Host and Local Signals .................................................................................. 5
Table 7 — Trace Lengths for Clock to SDRAM Load Net Structures ......................................................... 6
Table 8 — Trace Lengths for Address and Command Net Structures .......................................................... 7
Table 9 — Trace Lengths for Control Net Structures ................................................................................... 8
Table 10 — Trace Lengths for DQS[3:0]_[B:A]_t, DQS[3:0]_[B:A]_c, DQ[31:0]_[B:A],
DM[3:0]_[B:A]n ....................................................................................................................... 9