w9425g6dh Winbond Electronics Corp America, w9425g6dh Datasheet - Page 12

• Manufacturer Part Number: w9425g6dh
• Description: 4m X 4 Banks X 16 Bits Ddr Sdram
• Manufacturer: Winbond Electronics Corp America

7.2.16 Data Write Enable /Disable Command
7.3
Issuing the Bank Activate command to the idle bank puts it into the active state. When the Read
command is issued after t
synchronized with both edges of DQS (Burst Read operation). The initial read data becomes available
after CAS Latency from the issuing of the Read command. The CAS Latency must be set in the Mode
Register at power-up.
When the Precharge Operation is performed on a bank during a Burst Read and operation, the Burst
operation is terminated.
When the Read with Auto-precharge command is issued, the Precharge operation is performed
automatically after the Read cycle then the bank is switched to the idle state. This command cannot
be interrupted by any other commands. Refer to the diagrams for Read operation.
7.4
Issuing the Write command after t
sequentially, synchronizing with both edges(rising & falling) of DQS after the Write command (Burst
write operation). The burst length of the Write data (Burst Length) and Addressing Mode must be set
in the Mode Register at power-up.
When the Precharge operation is performed in a bank during a Burst Write operation, the Burst
operation is terminated.
When the Write with Auto-precharge command is issued, the Precharge operation is performed
automatically after the Write cycle, then the bank is switched to the idle state, The Write with Auto-
precharge command cannot be interrupted by any other command for the entire burst data duration.
Refer to the diagrams for Write operation.
(DM = "L/H" or LDM, UDM = "L/H")
During a Write cycle, the DM or LDM, UDM signal functions as Data Mask and can control every
word of the input data. The LDM signal controls DQ0 to DQ7 and UDM signal controls DQ8 to
DQ15.
Read Operation
Write Operation
RCD
from the Bank Activate command, the data is read out sequentially,
RCD
from the bank activate command. The input data is latched
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Publication Release Date:Feb. 12, 2008
W9425G6DH
Revision A8