Internet Data Sheet
HY[B/I]25DC512[80/16]0D[E/F](L)
512-Mbit Double-Data-Rate SDRAM
TABLE 16
Truth Table 5: Current State Bank n - Command to Bank m (different bank)
Current State CS RAS CAS WE Command
Action
Notes
1)2)3)4)5)6)
Any
H
L
X
H
X
X
H
X
X
H
X
Deselect
NOP. Continue previous operation
1)2)3)4)5)6)
1)2)3)4)5)6)
No Operation
NOP. Continue previous operation
–
Idle
X
Any Command
Otherwise Allowed to
Bank m
1)2)3)4)5)6)
Row
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
H
L
H
H
L
Active
Select and activate row
Select column and start Read burst
Select column and start Write burst
–
1)2)3)4)5)6)7)
1)2)3)4)5)6)7)
1)2)3)4)5)6)
Activating,
Active, or
Precharging
H
H
L
Read
L
Write
H
H
L
L
Precharge
Active
1)2)3)4)5)6)
Read (Auto
Precharge
Disabled)
L
H
H
L
Select and activate row
Select column and start new Read burst
–
1)2)3)4)5)6)7)
1)2)3)4)5)6)
H
L
Read
H
H
L
Precharge
Active
1)2)3)4)5)6)
Write (Auto
Precharge
Disabled)
L
H
H
L
Select and activate row
Select column and start Read burst
Select column and start new Write burst
–
1)2)3)4)5)6)7)8)
1)2)3)4)5)6)7)
1)2)3)4)5)6)
H
H
L
Read
L
Write
H
H
L
L
Precharge
Active
1)2)3)4)5)6)
Read (With
Auto
Precharge)
L
H
H
L
Select and activate row
Select column and start new Read burst
Select column and start Write burst
–
1)2)3)4)5)6)7)9)
1)2)3)4)5)6)7)9)10)
1)2)3)4)5)6)
H
H
L
Read
L
Write
H
H
L
L
Precharge
Active
1)2)3)4)5)6)
Write (With
Auto
Precharge)
L
H
H
L
Select and activate row
Select column and start Read burst
Select column and start new Write burst
–
1)2)3)4)5)6)7)9)
1)2)3)4)5)6)7)9)
1)2)3)4)5)6)
H
H
L
Read
L
Write
H
L
Precharge
1) This table applies when CKE n-1 was HIGH and CKE n is HIGH (see Table 14: Clock Enable (CKE) and after tXSNR/tXSRD has been met,
if the previous state was self refresh)
2) This table describes alternate bank operation, except where noted, i.e., the current state is for bank n and the commands shown are those
allowed to be issued to bank m (assuming that bank m is in such a state that the given command is allowable). Exceptions are covered in
the notes below.
3) Current state definitions: Idle: The bank has been precharged, and tRP has been met. Row Active: A row in the bank has been activated,
and tRCD has been met. No data bursts/accesses and no register accesses are in progress. Read: A Read burst has been initiated, with
Auto Precharge disabled, and has not yet terminated or been terminated. Write: A Write burst has been initiated, with Auto Precharge
disabled, and has not yet terminated or been terminated.
4) AUTO REFRESH and Mode Register Set commands may only be issued when all banks are idle.
5) A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state only.
6) All states and sequences not shown are illegal or reserved.
7) Reads or Writes listed in the Command/Action column include Reads or Writes with Auto Precharge enabled and Reads or Writes with
Auto Precharge disabled.
8) Requires appropriate DM masking.
9) Concurrent Auto Precharge:This device supports “Concurrent Auto Precharge”. When a read with auto precharge or a write with auto
precharge is enabled any command may follow to the other banks as long as that command does not interrupt the read or write data
Rev. 1.10, 2008-05
21
06212007-08MW-K87L
QIMONDA [ QIMONDA AG ]
