11
1Gbit (32Mx32bit) Mobile SDR Memory
H55S1G(2/3)2MFP Series
POWER DOWN
Power down occurs if CKE is set low coincident with Device Deselect or NOP command and when no accesses are in
progress. If power down occurs when all banks are idle, it is Precharge Power Down.
If Power down occurs when one or more banks are Active, it is referred to as Active power down. The device cannot
stay in this mode for longer than the refresh requirements of the device, without losing data. The power down state is
exited by setting CKE high while issuing a Device Deselect or NOP command.
If power-down occurs when all banks are idle, this mode is referred to as precharge power-down; if power-down
occurs when there is a row active in any bank, this mode is referred to as active power-down. Entering power-down
deactivates the input and output buffers, excluding CKE, for maximum power savings while in standby.
DEEP POWER-DOWN
The Deep Power-Down (DPD) mode enables very low standby currents. All internal voltage generators inside the
Mobile SDRAM are stopped and all memory data is lost in this mode.
All the information in the Mode Register and the Extended Mode Register is lost. Next Figure, DEEP POWER-DOWN
COMMAND shows the DEEP POWER-DOWN command All banks must be in idle state with no activity on the data bus
prior to entering the DPD mode. While in this state, CKE must be held in a constant low state.
To exit the DPD mode, CKE is taken high after the clock is stable and NOP command must be maintained for at least
200 us. After 200 us a complete re-initialization routing is required defined for the initialization sequence.
The below figure shows in case of 2KByte page size. If the page size is 4KByte, A0~A12 are provided.
CLK
CKE
CLK
CKE
CS
CS
RAS
CAS
WE
RAS
CAS
WE
A0~A13
BA0, 1
A0~A13
BA0, 1
Don't Care
Don't Care
DEEP POWER-DOWN COMMAND
POWER-DOWN COMMAND
Rev 1.2 / Jun. 2008
43
HYNIX [ HYNIX SEMICONDUCTOR ]
