LH28F320BJHE-PTTL90 Sharp Electronics, LH28F320BJHE-PTTL90 Datasheet - Page 11

• Manufacturer Part Number: LH28F320BJHE-PTTL90
• Manufacturer: Sharp Electronics

Specifications of LH28F320BJHE-PTTL90

• Cell Type: NOR
• Density: 32Mb
• Access Time (max): 90ns
• Interface Type: Parallel
• Boot Type: Top
• Address Bus: 22/21Bit
• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: -40C to 85C
• Package Type: TSOP
• Sync/async: Asynchronous
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 3.6V
• Word Size: 8/16Bit
• Number Of Words: 4M/2M
• Supply Current: 30mA
• Mounting: Surface Mount
• Pin Count: 48
• Lead Free Status / Rohs Status: Not Compliant

3 BUS OPERATION
The local CPU reads and writes flash memory in-system.
All bus cycles to or from the flash memory conform to
standard microprocessor bus cycles.
3.1 Read
Information can be read from any block, identifier codes
or status register independent of the V
can be at V
The first task is to write the appropriate read mode
command (Read Array, Read Identifier Codes or Read
Status Register) to the CUI. Upon initial device power-up
or after exit from reset mode, the device automatically
resets to read array mode. Six control pins dictate the data
flow in and out of the component: CE#, OE#, BYTE#,
WE#, RP# and WP#. CE# and OE# must be driven active
to obtain data at the outputs. CE# is the device selection
control, and when active enables the selected memory
device. OE# is the data output (DQ
when active drives the selected memory data onto the I/O
bus. BYTE# is the device I/O interface mode control.
WE# must be at V
and WP# must be at V
read cycle.
3.2 Output Disable
With OE# at a logic-high level (V
are disabled. Output pins (DQ
high-impedance state.
3.3 Standby
CE# at a logic-high level (V
standby mode which substantially reduces device power
consumption. DQ
impedance state independent of OE#. If deselected during
block erase, full chip erase, word/byte write or lock-bit
configuration, the device continues functioning, and
consuming active power until the operation completes.
sharp
IH
.
0
-DQ
IH
, RP# must be at V
IL
15
or V
outputs are placed in a high-
IH
IH
0
. Figure 16, 17 illustrates
-DQ
) places the device in
IH
0
), the device outputs
15
-DQ
CCW
) are placed in a
IH
15
, and BYTE#
) control and
voltage. RP#
LHF32J04
3.4 Reset
RP# at V
In read modes, RP#-low deselects the memory, places
output drivers in a high-impedance state and turns off all
internal circuits. RP# must be held low for a minimum of
100ns. Time t
mode until initial memory access outputs are valid. After
this wake-up interval, normal operation is restored. The
CUI is reset to read array mode and status register is set to
80H.
During block erase, full chip erase, word/byte write or
lock-bit configuration modes, RP#-low will abort the
operation. RY/BY# remains low until the reset operation
is complete. Memory contents being altered are no longer
valid; the data may be partially erased or written. Time
t
before another command can be written.
As with any automated device, it is important to assert
RP# during system reset. When the system comes out of
reset, it expects to read from the flash memory. Automated
flash memories provide status information when accessed
during block erase, full chip erase, word/byte write or
lock-bit configuration modes. If a CPU reset occurs with
no flash memory reset, proper CPU initialization may not
occur because the flash memory may be providing status
information instead of array data. SHARP’s flash
memories allow proper CPU initialization following a
system reset through the use of the RP# input. In this
application, RP# is controlled by the same RESET# signal
that resets the system CPU.
PHWL
is required after RP# goes to logic-high (V
IL
initiates the reset mode.
PHQV
is required after return from reset
Rev. 1.27
IH
9
)