hm5216805 Renesas Electronics Corporation., hm5216805 Datasheet - Page 31

• 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.

Read command to Write command interval
Same bank, same ROW address: When the write command is executed at the same ROW address of the
same bank as the preceding read command, the write command can be performed after an interval of no
less than 1 cycle. However, DQM must be set High so that the output buffer becomes High-Z before data
input.
READ to WRITE Command Interval-1
READ to WRITE Command Interval-2
Same bank, different ROW address: When the ROW address changes, consecutive write 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 write 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, DQM must be set High so
that the output buffer becomes High-Z before data input.
DQM
Command
Dout
Din
CLK
Dout
CL=3
CL=1
CL=2
Command
DQM
CL=3
CL=1
CL=2
CLK
Din
READ
READ WRIT
in B0
High-Z
in B1
HM5216805 Series, HM5216405 Series
in B2
2 clock
in B3
WRIT
High-Z
High-Z
High-Z
Burst Length = 4
Burst write
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