BSI
PIN DESCRIPTIONS
BS616LV4015
Name
A0-A17 Address Input
CE Chip Enable Input
Function
These 18 address inputs select one of the 262,144 x 16-bit words in the RAM.
CE is active LOW. Chip enables must be active when data read from or write to the
device. if chip enable is not active, the device is deselected and is in a standby power
mode. The DQ pins will be in the high impedance state when the device is deselected.
WE Write Enable Input
The write enable input is active LOW and controls read and write operations. With the
chip selected, when WE is HIGH and OE is LOW, output data will be present on the
DQ pins; when WE is LOW, the data present on the DQ pins will be written into the
selected memory location.
OE Output Enable Input
The output enable input is active LOW. If the output enable is active while the chip is
selected and the write enable is inactive, data will be present on the DQ pins and they
will be enabled. The DQ pins will be in the high impedance state when OE is inactive.
LB and UB Data Byte Control Input
DQ0 - DQ15 Data Input/Output
Ports
Vcc
Gnd
Lower byte and upper byte data input/output control pins.
These 16 bi-directional ports are used to read data from or write data into the RAM.
Power Supply
Ground
TRUTH TABLE
MODE
Not selected
(Power Down)
Output Disabled
Read
CE
H
L
L
WE
X
H
H
OE
X
H
L
LB
X
X
L
H
L
L
Write
L
L
X
H
L
UB
X
X
L
L
H
L
L
H
DQ0~DQ7
High Z
High Z
Dout
High Z
Dout
Din
X
Din
DQ8~DQ15
High Z
High Z
Dout
Dout
High Z
Din
Din
X
Vcc CURRENT
I
CCSB
, I
CCSB1
I
CC
I
CC
I
CC
I
CC
I
CC
I
CC
I
CC
R0201-BS616LV4015
2
Revision 2.4
April 2002