HYB25D512800BT Datasheet, PDF (56/90 Pages) Infineon Technologies AG – 512Mbit Double Data Rate SDRAM

HYB25D512[40/16/80]0B[E/F/C/T]
512Mbit Double Data Rate SDRAM
Functional Description
Table 10 Truth Table 2: Clock Enable (CKE)
Current State CKE n-1 CKEn
Command n
Action n
Notes
Self Refresh
Self Refresh
Previous
Cycle
L
L
Current
Cycle
L
H
X
Deselect or NOP
Maintain Self-Refresh
1)
Exit Self-Refresh
2)
Power Down L
L
X
Maintain Power-Down
–
Power Down L
H
Deselect or NOP
Exit Power-Down
–
All Banks Idle H
L
Deselect or NOP
Precharge Power-Down Entry –
All Banks Idle H
L
AUTO REFRESH
Self Refresh Entry
–
Bank(s) Active H
L
Deselect or NOP
Active Power-Down Entry
–
H
H
See Table 11
–
–
1) V_REF 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 (t_XSNR) period. A
minimum of 200 clock cycles are needed before applying a read command to allow the DLL to lock to the input clock.
Note:
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 11 Truth Table 3: Current State Bank n - Command to Bank n (same bank)
Current State CS
Any
H
L
Idle
L
L
L
Row Active L
L
L
Read (Auto L
Precharge
Disabled)
L
L
Write (Auto L
Precharge _L
Disabled)
L
RAS CAS WE
XXX
HHH
L HH
LLH
LLL
HL H
HL L
L HL
HL H
L HL
HHL
HL H
HL L
L HL
Command
Deselect
No Operation
Active
AUTO REFRESH
MODE
REGISTER SET
Read
Write
Precharge
Read
Precharge
BURST
TERMINATE
Read
Write
Precharge
Action
NOP. Continue previous operation.
NOP. Continue previous operation.
Select and activate row
–
–
Notes
1)2)3)4)5)6)
1) to 6)
1) to 6)
1) to 7)
1) to 7)
Select column and start Read burst
Select column and start Write burst
Deactivate row in bank(s)
Select column and start new Read
burst
Truncate Read burst, start
Precharge
BURST TERMINATE
1) to 6), 8)
1) to 6), 8)
1) to 6), 9)
1) to 6), 8)
1) to 6), 9)
1) to 6), 10)
Select column and start Read burst ^{1) to 6), 8), 11)}
Select column and start Write burst ^{1) to 6), 8)}
Truncate Write burst, start Precharge ^{1) to 6), 9), 11)}
1) This table applies when CKE n-1 was HIGH and CKE n is HIGH (see Table 10 and after t_XSNR/t_XSRD has been met (if the
previous state was self refresh).
2) This table is bank-specific, except where noted, i.e., the current state is for a specific bank and the commands shown are
those allowed to be issued to that bank when in that state. Exceptions are covered in the notes below.
Data Sheet
56
Rev. 1.2, 2004-06