W986408CH Datasheet, PDF (33/44 Pages) Winbond – 2M x 8BIT x 4 BANKS SDRAM

W986408CH
Autoprecharge Timing ( Read Cycle )
2M x 8 bit x 4 Banks SDRAM
0 1 2 3 4 5 6 7 8 9 10 11
(1) CAS Latency=2
( a ) burst length = 1
Command _{Read AP}
Act
tRP
DQ
Q0
( b ) burst length = 2
Command _Read
AP
Act
tRP
DQ
Q0 Q1
( c ) burst length = 4
Command _Read
AP
Act
tRP
DQ
Q0 Q1 Q2 Q3
( d ) burst length = 8
Command _Read
DQ
AP
Act
tRP
Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7
(2) CAS Latency=3
( a ) burst length = 1
Command
Read
AP
DQ
Act
tRP
Q0
( b ) burst length = 2
Command Read
DQ
AP
Act
tRP
Q0 Q1
( c ) burst length = 4
Command ^Read
DQ
AP
Act
tRP
Q0 Q1 Q2 Q3
( d ) burst length = 8
Command Read
DQ
AP
Act
tRP
Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7
Note )
Read
AP
Act
represents the Read with Auto precharge command.
represents the start of internal precharging.
represents the Bank Activate command.
Revision 1.0
When the Auto precharge command is asserted, the period from Bank Activate command to
the start of internal precgarging must be at least tRAS(min).
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Publication Release Date: March, 1999