m69ar048b STMicroelectronics, m69ar048b Datasheet - Page 6

• Manufacturer Part Number: m69ar048b
• Description: 32 Mbit 2mb X16 1.8v Asynchronous Psram
• Manufacturer: STMicroelectronics

M69AR048B
SIGNAL DESCRIPTIONS
See Figure 2, Logic Diagram, and Table 1, Signal
Names, for a brief overview of the signals connect-
ed to this device.
Address Inputs (A0-A20). The Address Inputs
select the cells in the memory array to access dur-
ing Read and Write operations.
Data Inputs/Outputs (DQ8-DQ15). The
Byte Data Inputs/Outputs carry the data to or from
the upper part of the selected address during a
Write or Read operation, when Upper Byte Enable
(UB) is driven Low.
Data Inputs/Outputs (DQ0-DQ7). The
Byte Data Inputs/Outputs carry the data to or from
the lower part of the selected address during a
Write or Read operation, when Lower Byte Enable
(LB) is driven Low.
Chip Enable (E1). When asserted (Low), the
Chip Enable, E1, activates the memory state ma-
chine, address buffers and decoders, allowing
Read and Write operations to be performed. When
de-asserted (High), all other pins are ignored, and
the device is put, automatically, in low-power
Standby mode.
Chip Enable (E2). The Chip Enable, E2, puts the
device in Power-down mode (Deep Power-Down
or a Partial Power-Down mode ) when it is driven
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Upper
Lower
Low. Deep Power-down mode is the lowest power
mode.
Output Enable (G). The Output Enable, G, pro-
vides a high speed tri-state control, allowing fast
read/write cycles to be achieved with the common
I/O data bus.
Write Enable (W). The Write Enable, W, controls
the Bus Write operation of the device.
Upper Byte Enable (UB). The Upper Byte En-
able, UB, gates the data on the Upper Byte Data
Inputs/Outputs (DQ8-DQ15) to or from the upper
part of the selected address during a Write or
Read operation.
Lower Byte Enable (LB). The Lower Byte En-
able, LB, gates the data on the Lower Byte Data
Inputs/Outputs (DQ0-DQ7) to or from the lower
part of the selected address during a Write or
Read operation.
V
supplies the power for all operations (Read, Write,
etc.) and for driving the refresh logic, even when
the device is not being accessed.
V
all voltage measurements.
CC
SS
Ground. The V
Supply Voltage. The V
SS
Ground is the reference for
CC
Supply Voltage