hm5264165f-75 Elpida Memory, Inc., hm5264165f-75 Datasheet - Page 28

• Manufacturer Part Number: hm5264165f-75
• Description: 64m Lvttl Interface Sdram
• Manufacturer: Elpida Memory, Inc.

HM5264165F/HM5264805F/HM5264405F-75/A60/B60
Command Intervals
Read command to Read command interval:
1. Same bank, same ROW address: When another read command is executed at the same ROW address
of the same bank as the preceding read command execution, the second read can be performed after an
interval of no less than 1 clock. Even when the first command is a burst read that is not yet finished, the data
read by the second command will be valid.
READ to READ Command Interval (same ROW address in same bank)
2. Same bank, different ROW address: When the ROW address changes on same bank, consecutive read
commands cannot be executed; it is necessary to separate the two read commands with a precharge command
and a bank-active command.
3. Different bank: When the bank changes, the second read can be performed after an interval of no less
than 1 clock, provided that the other bank is in the bank-active state. Even when the first command is a burst
read that is not yet finished, the data read by the second command will be valid.
READ to READ Command Interval (different bank)
28
Command
Command
Address
Address
Dout
Dout
CLK
CLK
BS
BS
Bank0
Active
Bank0
ACTV
Active
ACTV
Row
Row 0
Column =A
Read
Column A
ACTV
Bank3
Active
READ
Row 1
Data Sheet E0135H10
Column =B
Column B
Column A
READ
Bank0
READ
Read
Read
Column B
READ
Bank3
Read
Column =A
Dout
out A0 out B0
Bank0
Dout
Column =B
out A0 out B0
Dout
Bank3
Dout
out B1 out B2
out B1 out B2
out B3
out B3
CAS Latency = 3
Burst Length = 4
Bank 0
CAS Latency = 3
Burst Length = 4