W982516BH Datasheet, PDF (36/43 Pages) Winbond – 4M X 4 BANKS X 16 BIT SDRAM

W982516BH
Operating Timing Example, continued
Auto Precharge Timing (Write Cycle)
0
1
2
(1) CAS
Latency=2
( a ) burst length = 1
Command
Write
AP
tWR
tRP
DQ
D0
( b ) burst length = 2
Command
Write
DQ D0
AP
tWR
D1
( c ) burst length = 4
Command
Write
DQ D0 D1 D2
( d ) burst length = 8
Command
Write
3
4
Act
Act
tRP
AP
tWR
D3
DQ
(2) CAS
Latency=3
( a ) burst length = 1
Command
DQ
D0 D1
Write AP
tWR
D0
D2 D3
tRP
D4
Act
( b ) burst length = 2
Command
Write
DQ
( c ) burst length = 4
Command
D0
Write
AP
tWR
D1
DQ
( d ) burst length = 8
D0
D1
D2
Command _Write
tRP
AP
tWR
D3
DQ D0 D1 D2 D3 D4
5
6
Act
tRP
D5 D6
Act
tRP
D5 D6
7
8
AP
tWR
D7
Act
AP
tWR
D7
9
10 11
Act
tRP
Act
tRP
Note )
Write
represents the Write with Auto precharge
command.
AP
represents the start of internal
precharging.
Act
represents the Bank Activate
command.
When the Auto precharge command is asserted, the period from Bank
Acocmtivmataend _{to the start of internal precgarging must be at least tRAS (min).}
- 36 -