6
FUJITSU SEMICONDUCTOR CONFIDENTIAL
MB86R12 Application Note
DDR3 Interface PCB
Design Guideline
4.4.
Terminal resistance/Damping resistance/Wire length
Table 4-2 shows the recommended resistance value and wire length for each group.
The wiring topology diagram relevant to this section is shown in "4.7. Wiring topology".
Table 4-2 Resistance value and wire length list
No.
Group name
External terminal
resistance value
(Rt)
Damping
resistance value
(Rd)
Wire length from
MB86R12 output to
SDRAM input
Internal group approved
wire length variation
1 MCK_Group
39
Ω × 2
0.1μF capacitor × 1
(
Refer to "4.7.1
.")
N/A
Refer to "4.7.1
."
Meet the conditions of
"4.7.1
."
2 MDQSx_Group
N/A
N/A
Refer to "
4.7.2."
Meet the conditions of
"
4.7.2."
3 MDQx_Group
N/A
N/A
Refer to "
4.7.3."
Meet the conditions of
"
4.7.3."
4 MCNTL_Group
39Ω
N/A
Refer to "
4.7.4."
Meet the conditions of
"
4.7.4."
5 MCMD_Group
39Ω
N/A
Refer to "
4.7.4."
Meet the conditions of
"
4.7.4."
