SMJ44C251B Datasheet, PDF (27/53 Pages) Texas Instruments – 262144 BY 4-BIT MULTIPORT VIDEO RAM

SMJ44C251B
262144 BY 4-BIT
MULTIPORT VIDEO RAM
SGMS058A – MARCH 1995 – REVISED JUNE 1995
PARAMETER MEASUREMENT INFORMATION
RAS
tw(RL)
tc(W)
tt
CAS
td(CHRL)
td(RLCL)
th(RA)
td(RLCH)
td(CLRH)
tw(CL)
td(RLCA)
tsu(RA)
th(RLCA)
tsu(CA)
td(CARH)
th(CLCA)
A0 – A8
Row
Column
tw(RH)
tt
td(CHRL)
tw(CH)
tsu(SFR)
th(SFR)
DSF
1
th(RSF)
th(SFC)
tsu(SFC)
2
TRG
W
DQ0 – DQ3
tsu(TRG)
th(RWM)
td(GHD)
tsu(WMR)
th(RLW)
tsu(WRH)
th(WLG)
tsu(WCH)
th(CLW)
3
tsu(DWL)
tsu(DQR)
th(RDQ)
th(RLD)
tw(WL)
th(WLD)
4
5
Figure 15. Delayed-Write-Cycle Timing (Output-Enable-Controlled Write)
Table 5. Write-Cycle State Table
CYCLE
Write operation
Write-mask load/use, write DQs to I/Os
Use previous write mask, write DQs to I/Os
Load write mask on later of W fall and CAS fall
1
2
L
L
L
L
H
L
H
L
STATE
3
H
L
L
H
4
Don’t care
Write mask
Don’t care
Don’t care
5
Valid data
Valid data
Valid data
Write mask
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