hm5216805 Renesas Electronics Corporation., hm5216805 Datasheet - Page 32

• Manufacturer Part Number: hm5216805
• Description: 16 M Lvttl Interface Sdram 100 Mhz/83 Mhz 1-mword 8-bit 2-bank/2-mword 4-bit 2-bank - Hitachi Semiconductor
• Manufacturer: Renesas Electronics Corporation.

HM5216805 Series, HM5216405 Series
Write command to Read command interval
Same bank, same ROW address: When the read command is executed at the same ROW address of the
same bank as the preceding write command, the read command can be performed after an interval of no
less than 1 cycle. However, in the case of a burst write, data will continue to be written until one cycle
before the read command is executed.
WRITE to READ Command Interval-1
WRITE to READ Command Interval-2
Same bank, different ROW address: When the ROW address changes, consecutive read commands
cannot be executed; it is necessary to separate the two commands with a precharge command and a bank-
active command.
Different bank: When the bank changes, the read command can be performed after an interval of no less
than 1 cycle, provided that the other bank is in the bank-active state. However, in the case of a burst write,
data will continue to be written until one cycle before the read command is executed (as in the case of the
same bank and the same address).
32
Command
Command
DQM
DQM
Dout
CLK
Dout
CLK
Din
Din
WRIT
Column=A
Write
in A0
Column=A
WRIT
Write
in A0
in A1
READ
Column=B
Read
CAS Latency
READ
Column=B
Read
CAS Latency
Column=B
Dout
out B0
Column=B
Dout
out B0
out B1
out B1
out B2
out B2
out B3
out B3
Burst Write Mode
CAS Latency = 1
Burst Length = 4
Bank = 0
Burst Write Mode
CAS Latency = 1
Burst Length = 4
Bank = 0