W641GG2JB Datasheet, PDF (40/109 Pages) Winbond – 1-Gbit GDDR3 Graphics SDRAM

W641GG2JB
6.5.3 Dynamic Switching of DQ terminations
1-Gbit GDDR3 Graphics SDRAM
The GDDR3 Graphics RAM will disable its data terminators when a READ or DTERDIS command is detected. The terminators are
disabled starting at CL - 1 Clocks after the READ / DTERDIS command is detected and the duration is 4 clocks. In a two rank
system, both devices will snoop the bus for a READ / DTERDIS command to either device and both will disable their terminators if
a READ / DTERDIS command is detected. The address and command terminators are always enabled.
6.5.3.1 ODT Disable Timing during a READ command
0
1
2
3
4
5
6
7
8
9
CLK#
CLK
Com.
RD
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
Add.
B/C
RDQS
DQ
DQ
Termination
CAS Iatency = 5
D0 D1 D2 D3
Data Terminations are disabled
Dx : Data from B / C
Com. : Command
Addr. : Address B / C
Don‘t care
B / C : Bank / Column address
RD : READ
N / D : NOP or Deselect
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Publication Release Date: Apr, 22, 2011
Revision A01-002