Datasheet

Self Refresh Exit with No Operation command
Self Refresh Exit with No Operation command (NOP) allows for a common command/address bus between
active DRAM and DRAM in Max Power Saving Mode. Self Refresh Mode may exit with No Operation
commands (NOP) provided:
 The DRAM entered Self Refresh Mode with CA Parity and CAL disabled.
 t
MPX_S
and t
MPX_LH
are satisfied.
 NOP commands are only issued during t
MPX_LH
window.
No other command is allowed during t
MPX_LH
window after SRX command is issued.
t
CKSRX
NOPSRX
1,2
NOP NOP NOP DES DES DES
VALID
t
MPX_S
NOTE 1. CS# = L, ACT# = H, RAS#/A16 = H, CAS#/A15 = H, WE#/A14 = H at Tb2 ( No Operation command )
NOTE 2. SRX at Tb2 is only allowed when DRAM shared Command/Address bus is under exiting Max Power Saving Mode.
NOTE 3. Valid commands not requiring a locked DLL
NOTE 4. Valid commands requiring a locked DLL
NOTE 5. t
XS_FAST
and t
XS_ABORT
are not allowed this case.
NOTE 6. Duration of CS# Low around CKE rising edge must satisfy t
MPX_S
and t
MPX_LH
as defined by Max Power Saving Mode AC parameters.
DON'T CARETIME BREAK
VALID
t
MPX_LH
t
XS
t
XS
+ t
XSDLL
Ta1 Ta2 Ta3 Tb0 Tb2 Tc1 Tc2 Tc3 Td0 Td1 Td2 Td3
Tb1 Tb3 Tc0
VALID VALID
Tc4 Te0 Te1
DES DES VALID
3
DES VALID
4
VALID
VALIDVALID
CK#
CK
CMD
ODT
ADDR
CS#
CKE
Figure 26. Self Refresh Exit with No Operation command
AS4C256M16D4
Confidential
- 46 of 201 -
Rev.1.0 Aug.2019