EDJ1108BABG, EDJ1116BABG
DLL “off” to DLL “on” Procedure
To Switch from DLL “off” to DLL “on” (with required frequency change) during Self-Refresh:
1. Starting from Idle state (all banks pre-charged, all timings fulfilled and DRAMs On-die Termination resistors (RTT)
must be in high impedance state before Self-Refresh mode is entered.)
2. Enter Self-refresh Mode, wait until tCKSRE satisfied.
3. Change frequency, in guidance with Input Clock Frequency Change during Precharge Power-Down section.
4. Wait until a stable clock is available for at least (tCKSRX) at DRAM inputs.
5. Starting with the self-refresh exit command, CKE must continuously be registered high until all tDLLK timing from
subsequent DLL Reset command is satisfied. In addition, if any ODT features were enabled in the mode
registers when Self-refresh mode was entered, the ODT signal must continuously be registered low until tDLLK
timings from subsequent DLL Reset command is satisfied. If both ODT features are disabled in the mode
registers when Self Refresh mode was entered, ODT signal can be registered low or high.
6. Wait tXS, then set MR1 bit A0 to “0” to enable the DLL.
7. Wait tMRD, then set MR0 bit A8 to “1” to start DLL Reset.
8. Wait tMRD, and then set Mode Registers with appropriate values (especially an update of CL, CWL and WR may
be necessary. After tMOD is satisfied from any proceeding MRS command, a ZQCL command may also be
issued during or after tDLLK.)
9. Wait for tMOD, and then DRAM is ready for next command (remember to wait tDLLK after DLL Reset before
applying command requiring a locked DLL!). In addition, wait also for tZQoper in case a ZQCL command was
issued.
Ta
Tb
Tc Tc+1Tc+2
Td
Te
Tf Tf+1Tf+2
Tg
CK
/CK
tCKSRE
tCKSRX
tDLLK
MRS
tXS
tMRD tMRD
SRE NOP
SRX
MRS
MRS
Valid
Command
CKE
tCKESR
ODTLoff + 1x tCK
ODT
Change Frequency
DLL Switch Sequence from DLL-Off to DLL-On
Data Sheet E1248E40 (Ver. 4.0)
82
ELPIDA [ ELPIDA MEMORY ]
