43

Rev. 0A | October 2022

www.issi.com - dram@issi.com

IS43/46LR32320C

IS43/46LR16640C

Figure35 : Power down (Active or Precharge)

Figure36 : Deep Power down

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. A valid command can be issued after tXP.

Deep Power down

The Deep Power-Down (DPD) mode enables very low standby currents. All internal voltage generators inside the Mobile DDR 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.

VALID

NOP

NOP

VALID

/CLK

CLK

CKE

T0

Command

T1

Ta0

tCH

tCL

DQS, DQ, DM

tIS

tIH

VALID

Address

tCK

VALID

tIS

tIS

tIH

tIS

tIH

T2

Ta1

Tb0

Must not exceed refresh device limits

Don’t care

Power-down mode entry

Power-down mode exit

t XP

VALID

NOP

NOP

DPD

NOP

/CLK

CLK

CKE

T0

Command

T1

Ta0

DQS, DQ, DM

Tb0

Address

tCKE

VALID

tIS

T2

Ta1

Ta2

Don’t care

Deep Power -down mode

entry

Deep Power-down mode

exit

T=200us