11
1Gbit (32Mx32bit) Mobile SDR Memory
H55S1G(2/3)2MFP 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-A13(only for the 2KBytes page size. For the
4KBytes page size, A0~A12 are provided) selects the row. This row remains active (or open) for accesses until a PRE-
CHARGE command is issued to that bank. (see to next figure)
CLK
CKE
CLK
CKE
(High)
(High)
CS
CS
RAS
RAS
CAS
WE
CAS
WE
RA
BA
A0~A13
BA0,1
A0~A13
BA0,1
Row Address
Bank Address
Don't Care
Don't Care
ACTIVATING A SPECIFIC
ROW IN A SPECIFIC BANK
NOP command
Rev 1.2 / Jun. 2008
26
HYNIX [ HYNIX SEMICONDUCTOR ]
