HY5S7B2ALFP-6 Datasheet, PDF (26/53 Pages) Hynix Semiconductor – 512M (16Mx32bit) Mobile SDRAM

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512Mbit (16Mx32bit) Mobile SDR Memory
HY5S7B2ALF(P) Series
DESELECT
The DESELECT function (CS = High) prevents new commands from being executed by the Mobile SDRAM, the Mobile
SDRAM ignore command input at the clock. However, the internal status is held. The Mobile SDRAM is effectively dese-
lected. Operations already in progress are not affected.
NO OPERATION
The NO OPERATION (NOP) command is used to perform a NOP to a Mobile SDRAM that is selected (CS = Low, RAS =
CAS = WE = High). This command is not an execution command. However, the internal operations continue. This pre-
vents unwanted commands from being registered during idle or wait states. Operations already in progress are not
affected. (see to next figure)
ACTIVE
The Active command is used to activate a row in particular bank for a subsequent Read or Write access. The value of
the BA0,BA1 inputs selects the bank, and the address provided on A0-A12(or the highest address bit) selects the row.
This row remains active (or open) for accesses until a PRECHARGE command is issued to that bank. (see to next fig-
ure)
CLK
CKE
CS
RAS
CAS
WE
A0~A9,
A12
BA0,1
High-Z
CLK
CKE
High-Z
CS
RAS
CAS
WE
NOP command
A0~A9,
A12
BA0,1
Don't Care
RA
Row Address
BA
Bank Address
Don't Care
ACTIVATING A SPECIFIC
ROW IN A SPECIFIC BANK
Rev 1.2 / Nov. 2008
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