msm548262 Oki Semiconductor, msm548262 Datasheet - Page 29

• Manufacturer Part Number: msm548262
• Description: 262,144-word 8-bit Multiport Dram
• Manufacturer: Oki Semiconductor

¡ Semiconductor
OPERATION MODES
Table-1 shows the function truth table for a listing of all available RAM ports, and transfer
operation of MSM548262.
The RAM port and data transfer operations are determined by the state of CAS, TRG, WE and
DSF at the falling edge of RAS, and by the level of DSF at the falling edge of CAS.
If the DSF is "high" at the falling edge of RAS, special functions such as split transfer, flash write,
load color register can be invoked.
If the DSF is "low" at the falling edge of RAS and "high" at the falling edge of CAS, the block write
feature can be invoked.
MSWT
Code
RWM
BWM
MWT
FWM
ROR
CBR
SRT
LCR
RW
BW
RT
CAS TRG WE DSF DSF
0
1
1
1
1
1
1
1
1
1
1
1
RASØ
*
1
0
0
0
0
1
1
1
1
1
1
*
*
0
0
1
1
0
0
0
1
1
1
*
0
0
1
0
1
0
0
1
0
0
1
CASØ
—
— Row
*
*
*
*
0
1
*
0
1
1
RASØ
Row TAP WM1
Row TAP WM1
Row TAP
Row TAP
Row
Row
Row
Row
Row
Row
Address
Table-1. Function Truth Table
*
A2c - 8c
A2c - 8c
CASØ
Column
Column
Column
Column
—
*
*
*
RASØ
WM1
WM1
WM1 —
*
*
*
*
*
*
*
W/IO
Din, Dout
Din, Dout
Column
Column
/WEØ
Select
Select
Color
CAS
Data
—
*
*
*
*
*
Mask
Write
Yes
Yes
Yes
Yes
Yes
No
No
—
—
—
—
—
Register
Color
Load
Use
Use
Use
—
—
—
—
—
—
—
—
CBR Refresh
RAS Only Refresh
Masked Write Transfer
Masked Split
Write Transfer
Read Transfer
Split Read Transfer
Read/Write
(Mask)
Masked Block Write
Masked Flash Write
Read/Write
(No Mask)
Block Write
(No Mask)
Load Color Register
Function
MSM548262
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