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HYB18T512400AC5 Datasheet, PDF (66/96 Pages) Infineon Technologies AG – 512-Mbit Double-Data-Rate-Two SDRAM
HYB18T512[400/800/160]A[C/F]–[3.7/5]
512-Mbit Double-Data-Rate-Two SDRAM
Truth Tables
Table 17 Clock Enable (CKE) Truth Table for Synchronous Transitions
Current State1) CKE
Command (N)2) 3) Action (N)2)
Notes4)5)
Previous Cycle6) Current Cycle6)
(N-1)
(N)
RAS, CAS, WE, CS
Power-Down L
L
X
Maintain Power-Down 7)8)11)
L
H
DESELECT or NOP Power-Down Exit
9)10)11)7)
Self Refresh L
L
X
Maintain Self Refresh
11)8)12)
L
H
DESELECT or NOP Self Refresh Exit
9)13)14)12)
Bank(s)
H
Active
L
DESELECT or NOP Active Power-Down Entry 9)10)15)11)7)
All Banks Idle H
L
DESELECT or NOP Precharge Power-Down 9)10)15)11)
Entry
H
L
AUTOREFRESH Self Refresh Entry
16)14)11)7)
Any State other H
than
listed above
H
Refer to the Command Truth Table
17)
1) Current state is the state of the DDR2 SDRAM immediately prior to clock edge N.
2) Command (N) is the command registered at clock edge N, and Action (N) is a result of Command (N)
3) The state of ODT does not affect the states described in this table. The ODT function is not available during Self Refresh.
4) CKE must be maintained high while the device is in OCD calibration mode.
5) Operation that is not specified is illegal and after such an event, in order to guarantee proper operation, the DRAM must
be powered down and then restarted through the specified initialization sequence before normal operation can continue.
6) CKE (N) is the logic state of CKE at clock edge N; CKE (N-1) was the state of CKE at the previous clock edge.
7) The Power-Down Mode does not perform any refresh operations. The duration of Power-Down Mode is therefor limited by
the refresh requirements
8) “X” means “don’t care (including floating around VREF)” in Self Refresh and Power Down. However ODT must be driven
high or low in Power Down if the ODT function is enabled (Bit A2 or A6 set to “1” in EMRS(1)).
9) All states and sequences not shown are illegal or reserved unless explicitly described elsewhere in this document.
10) Valid commands for Power-Down Entry and Exit are NOP and DESELECT only.
11) Minimum CKE high time is 3 clocks, minimum CKE low time is 3 clocks.
12) VREF must be maintained during Self Refreh Operation
13) On Self Refresh Exit DESELECT or NOP commands must be issued on every clock edge occurring during the tXSNR
period. Read commands may be issued only after tXSRD (200 clocks) is satisfied.
14) Valid commands for Self Refresh Exit are NOP and DESELCT only.
15) Power-Down and Self Refresh can not be entered while Read or Write operations, (Extended) mode Register operations,
Precharge or Refresh operations are in progress. See Chapter 2.10 and Chapter 2.9.2 for a detailed list of restrictions.
16) Self Refresh mode can only be entered from the All Banks Idle state.
17) Must be a legal command as defined in the Command Truth Table.
Table 18 Data Mask (DM) Truth Table
Name (Function)
Write Enable
Write Inhibit
DM
DQs
Notes
L
Valid
1)
H
X
1)
1) Used to mask write data; provided coincident with the corresponding data.
Data Sheet
66
Rev. 1.13, 2004-05
09112003-SDM9-IQ3P