W641GG2JB Datasheet, PDF (18/109 Pages) Winbond – 1-Gbit GDDR3 Graphics SDRAM

W641GG2JB
1-Gbit GDDR3 Graphics SDRAM
6. FUNCTIONAL DESCRIPTION
This section describe the unitization sequence of the GDRAM. It has been divided in to parts for each of the operations modes (1-CS
or 2-CS). In the initialization, and before the choice of the operation mode by Mode Registration Set command, the default mode is
1-CS this implies a common initialization sequence up to point 7.
6.1 System Configurations
Figure shows typical system configurations for 1-CS mode and 2-CS mode.
2-CS mode is equivalent to a clamshell configuration with two 512Mbit devices (rank 0 and rank 1) sharing a common interface; it
benefits from the single physical pin load of this monolithic solution.
In 1-CS mode the device is addressed as a single 8-bank device, and the MSB row address A12 selects between the upper and
lower half of the die.
6.1.1 System Configurations in 1-CS Mode and 2-CS Mode
1-CS Mode
Controller
CS0#
CLK,CLK#
ADDR/CMD
DQ0-DQ31
DM0-DM3
WDQS0-WDQS3
RDQS0-RDQS3
1Gbit
GDDR3
SDRAM
2-CS Mode
1Gbit GDDR3
SDRAM
512Mbit
GDDR3 SDRAM
(Rank 0)
Controller
CS0#
CS1#
CLK,CLK#
ADDR/CMD
DQ0-DQ31
DM0-DM3
WDQS0-WDQS3
RDQS0-RDQS3
512Mbit
GDDR3 SDRAM
(Rank 1)
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Publication Release Date: Apr, 22, 2011
Revision A01-002