Internet Data Sheet
HYB25DC128[800/160]C[E/F]
128-Mbit Double-Data-Rate SDRAM
TABLE 11
Truth Table 2: Clock Enable (CKE)
Current State CKE n-1
Previous Cycle
CKEn
Command n
Action n
Note
Current Cycle
1)
2)
Self Refresh
Self Refresh
Power Down
Power Down
All Banks Idle
All Banks Idle
Bank(s) Active
L
L
X
Maintain Self-Refresh
Exit Self-Refresh
L
H
L
Deselect or NOP
X
L
Maintain Power-Down
Exit Power-Down
—
—
—
—
—
—
L
H
L
Deselect or NOP
Deselect or NOP
AUTO REFRESH
Deselect or NOP
See Table 12
H
H
H
H
Precharge Power-Down Entry
Self Refresh Entry
Active Power-Down Entry
—
L
L
H
1)
VREF must be maintained during Self Refresh operation
2) Deselect or NOP commands should be issued on any clock edges occurring during the Self Refresh Exit (tXSNR) period. A minimum of 200
clock cycles are needed before applying a read command to allow the DLL to lock to the input clock.
Notes
1. CKEn is the logic state of CKE at clock edge n: CKE n-1 was the state of CKE at the previous clock edge.
2. Current state is the state of the DDR SDRAM immediately prior to clock edge n.
3. COMMAND n is the command registered at clock edge n, and ACTION n is a result of COMMAND n.
4. All states and sequences not shown are illegal or reserved.
TABLE 12
Truth Table 3: Current State Bank n - Command to Bank n (same bank)
Current State CS
RAS CAS WE Command
Action
Note
1)2)3)4)5)6)
Any
H
L
L
L
L
X
H
L
X
H
H
L
X
H
H
H
L
Deselect
NOP. Continue previous operation.
1) to 6)
1) to 6)
1) to7)
1) to 7)
No Operation
Active
NOP. Continue previous operation.
Idle
Select and activate row
L
AUTO REFRESH
—
—
L
L
MODE REGISTER
SET
1) to 6),8)
1) to 6),8)
1) to 6),9)
1) to 6),8)
1) to 6),9)
1) to 6),10)
Row Active
L
L
L
L
L
L
H
H
L
L
H
L
Read
Select column and start Read burst
Select column and start Write burst
Deactivate row in bank(s)
L
Write
H
L
L
Precharge
Read
Read (Auto
Precharge
Disabled)
H
L
H
L
Select column and start new Read burst
Truncate Read burst, start Precharge
BURST TERMINATE
H
H
Precharge
H
L
BURST
TERMINATE
1) to 6),8),11)
1) to 6),8)
Write (Auto
Precharge
Disabled)
L
L
L
H
H
L
L
L
H
H
L
L
Read
Select column and start Read burst
Select column and start Write burst
Truncate Write burst, start Precharge
Write
1) to 6),9),11)
Precharge
Rev. 1.1, 2007-01
03062006-JXUK-E7R1
15
QIMONDA [ QIMONDA AG ]
