W641GG2JB Datasheet, PDF (34/109 Pages) Winbond – 1-Gbit GDDR3 Graphics SDRAM

W641GG2JB
1-Gbit GDDR3 Graphics SDRAM
The steps 1 and 2 are necessary to enable the termination for the command/address pins. They are part of the regular SGRAM
Initialization. They are required if the user wants to issue commands between to entering of the boundary scan functionality and the
power-up sequence. The entering of the boundary scan mode is resetting the command/address termination values and all
EMRS/MRS settings. Therefore they have to be initialized again after the boundary scan functionary has been left. Figure
(Boundary Scan Exit Sequence)shows the scan initialization sequence for regular SGRAM operation.
6.4.4.1 Scan Initialization Sequence within regular SGRAM Mode
VDD
VDDQ
VREF
CLK/CLK#
SSH [RES]
tATS tATH
CKE
tSDS tSDH
VALID
tSCS tSCH
tSDS tSDH
VALID
tSCS tSCH
SEN
SCK[CS#]
SOE[MF]
SOUT[WDQS]
Pins
Under
Test
T = 200 us
700 tCK
Power-up :
VDD stable
RESET at power - up
tSES
tSCS
tSDS tSDH
VALID
tSCS
ScanOut Bit 0
Boundary Scan Mode
Don‘t care
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Publication Release Date: Apr, 22, 2011
Revision A01-002