hyb18t512160afl-3.7 Infineon Technologies Corporation, hyb18t512160afl-3.7 Datasheet - Page 72

• Manufacturer Part Number: hyb18t512160afl-3.7
• Description: 512-mbit Ddr2 Sdram
• Manufacturer: Infineon Technologies Corporation

Figure 60
Figure 61
3.26
3.26.1
The No Operation Command (NOP) should be used in
cases when the SDRAM is in a idle or a wait state. The
purpose of the No Operation Command is to prevent
the SDRAM from registering any unwanted commands
between operations. A No Operation Command is
3.26.2
The Deselect Command performs the same function as
a No Operation Command. Deselect Command occurs
3.27
During operation the DRAM input clock frequency can
be changed under the following conditions:
•
•
In the Precharge Power-down mode the DDR2-
SDRAM has to be in Precharged Power-down mode
Data Sheet
During Self-Refresh operation
DRAM is in Precharge Power-down mode and ODT
is completely turned off.
C K , C K
C K E
C M D
C K , C K
C K E
C M D
Auto-Refresh command to Power-Down entry
MRS, EMRS command to Power-Down entry
Other Commands
No Operation Command
Deselect Command
Input Clock Frequency Change
T0
T0
Refresh
Auto
T1
MRS or
EMRS
T1
T2
CKE can go low one clock after an Auto-Refresh command
When tRFC expires the DRAM is in Precharge Power-Down Mode
T2
t
MRD
tRFC
T3
T3
Enters Precharge Power-Down Mode
T4
T4
73
registered when CS is LOW with RAS, CAS, and WE
held HIGH at the rising edge of the clock. A No
Operation Command will not terminate a previous
operation that is still executing, such as a burst read or
write cycle.
when CS is brought HIGH, the RAS, CAS, and WE
signals become don’t care.
and idle. ODT must be already turned off and CKE must
be at a logic LOW state. After a minimum of two clock
cycles after
clock frequency can be changed. A stable new clock
frequency has to be provided, before CKE can be
changed to a HIGH logic level again. After
satisfied a DLL RESET command via EMRS(1) has to
HYB18T512[40/80/16]0AF(L)–[3/3S/3.7/5]
T5
t
RP
tis
T6
and
Tn
t
AOFD
tXP
T7
512-Mbit DDR2 SDRAM
have been satisfied the input
Functional Description
09112003-SDM9-IQ3P
Command
Rev. 1.6, 2005-08
Valid
MRS_PD
t
ARPD
XP
has been