HYB25D256161CE Datasheet, PDF (43/72 Pages) Infineon Technologies AG – 16M x 16 Double Data Rate Graphics DRAM

HYB25D256161CE-[4/5]
256-Mbit Double Data Rate SGRAM
Functional Description
Table 7 Truth Table 2: Clock Enable (CKE)
Current State CKE n-1
Previous
Cycle
Self Refresh L
Self Refresh L
Power Down L
Power Down L
All Banks Idle H
All Banks Idle H
Bank(s) Active H
H
CKEn
Current
Cycle
L
H
L
H
L
L
L
H
Command n
X
Deselect or NOP
X
Deselect or NOP
Deselect or NOP
AUTO REFRESH
Deselect or NOP
See Table 8
Action n
Notes
Maintain Self-Refresh
–
Exit Self-Refresh
1)
Maintain Power-Down
–
Exit Power-Down
–
Precharge Power-Down Entry –
Self Refresh Entry
–
Active Power-Down Entry
–
–
–
1) 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.
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 SGRAM 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 8 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 7 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.
Datasheet
43
Rev.1.0, 2004-02