The LH28F800BG-L/BGH-L flash memories with
SmartVoltage technology are high-density, low-cost,
nonvolatile, read/write storage solution for a wide
range of applications. The LH28F800BG-L/BGH-L
can operate at V
low voltage operation capability realizes longer
battery life and suits for cellular phone application.
Their boot, parameter and main-blocked
architecture, flexible voltage and enhanced cycling
capability provide for highly flexible component
suitable for portable terminals and personal
computers. Their enhanced suspend capabilities
provide for an ideal solution for code + data storage
applications. For secure code storage applications,
such as networking, where code is either directly
executed out of flash or downloaded to DRAM, the
LH28F800BG-L/BGH-L offer two levels of protection
: absolute protection with V
hardware boot block locking. These alternatives
give designers ultimate control of their code security
needs.
CC = 2.7 V and VPP = 2.7 V. Their
PP at GND, selective
FEATURES
• SmartVoltage technology
– 2.7 V, 3.3 V or 5 V V
– 2.7 V, 3.3 V, 5 V or 12 V VPP
• High performance read access time
LH28F800BG-L85/BGH-L85
– 85 ns (5.0±0.25 V)/90 ns (5.0±0.5 V)/
• Low power management
– Deep power-down mode
– Automatic power saving mode decreases I
in static mode
• Automated word write and block erase
– Command user interface
– Status register
TM
∗
• ETOX
• Packages
– 48-pin TSOP Type I (TSOP048-P-1220)
– 48-ball CSP (FBGA048-P-0808)
∗ ETOX is a trademark of Intel Corporation.
V nonvolatile flash technology
Normal bend/Reverse bend
Flash Memories
PP = GND
IL
CC
In the absence of confirmation by device specification sheets, SHARP takes no responsibility for any defects that may occur in equipment using any SHARP devices shown in catalogs, data books,
etc. Contact SHARP in order to obtain the latest device specification sheets before using any SHARP device.
∗1 Refer to the datasheet of LH28F800BG-L (FOR SOP).
OPERATING
TEMPERATURE
0 to +70°C
– 40 to +85°C
1
∗
PACKAGE
48-pin TSOP (I)
48-ball CSPWP# and
48-pin TSOP (I)
48-ball CSPWP# and
0 to +70°C44-pin SOP10 µAControlled by RP# pin
PIN CONNECTIONS
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
DC CHARACTERISTICS
VCCdeep power-down current (MAX.)
10 µA
20 µA
WRITE PROTECT FUNCTION
FOR BOOT BLOCKS
Controlled by
Controlled by
RP# pins
RP# pins
TOP VIEW
NOTE :
Reverse bend available on request.
- 2 -
BLOCK ORGANIZATION
INPUT
BUFFERBUFFER
OUTPUT
MULTIPLEXER
VCC
CE#
RP#
OE#
IDENTIFIER
REGISTER
COMMAND
USER
INTERFACE
WRITE
STATE
MACHINE
PROGRAM/ERASE
VOLTAGE SWITCH
I/O
LOGIC
STATUS
REGISTER
DATA
REGISTER
DATA
COMPARATOR
15
32 k-WORD
MAIN BLOCKS
X
DECODER
Y
DECODER
Y GATING
RY/BY#
V
PP
V
CC
GND
A0-A18
INPUT
BUFFER
ADDRESS
LATCH
ADDRESS
COUNTER
BOOT BLOCK 0
BOOT BLOCK 1
PARAMETER BLOCK 0
PARAMETER BLOCK 1
PARAMETER BLOCK 2
PARAMETER BLOCK 3
PARAMETER BLOCK 4
PARAMETER BLOCK 5
MAIN BLOCK 0
MAIN BLOCK 1
MAIN BLOCK 13
MAIN BLOCK 14
WP#
WE#
OUTPUT
DQ0-DQ15
This product features an asymmetrically-blocked
architecture providing system memory integration.
Each erase block can be erased independently of
the others up to 100 000 times. For the address
locations of the blocks, see the memory map in
Fig. 1.
Boot Blocks : The two boot blocks are intended to
replace a dedicated boot PROM in a microprocessor or microcontroller-based system. The
boot blocks of 4 k words (4 096 words) feature
hardware controllable write-protection to protect the
crucial microprocessor boot code from accidental
modification. The protection of the boot blocks is
controlled using a combination of the V
PP, RP# and
WP# pins.
BLOCK DIAGRAM
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
Parameter Blocks : The boot block architecture
includes parameter blocks to facilitate storage of
frequently update small parameters that would
normally require an EEPROM. By using software
techniques, the byte-rewrite functionality of
EEPROMs can be emulated. Each boot block
component contains six parameter blocks of 4 k
words (4 096 words) each. The parameter blocks
are not write-protectable.
Main Blocks : The reminder is divided into main
blocks for data or code storage. Each 8 M-bit
device contains fifteen 32 k words (32 768 words)
blocks.
- 3 -
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
PIN DESCRIPTION
SYMBOLTYPENAME AND FUNCTION
A
0-A18INPUT
DQ0-DQ15
INPUT/
OUTPUT
CE#INPUT
RP#INPUT/
OE#INPUTOUTPUT ENABLE : Gates the device’s outputs during a read cycle.
WE#INPUT
WP#INPUT
RY/BY#OUTPUT
V
PPSUPPLY
V
CCSUPPLY
GNDSUPPLYGROUND : Do not float any ground pins.
NCNO CONNECT : Lead is not inter nal connected; recommend to be floated.
ADDRESS INPUTS : Inputs for addresses during read and write operations. Addresses
are internally latched during a write cycle.
DATA INPUT/OUTPUTS : Inputs data and commands during CUI write cycles; outputs
data during memory array, status register and identifier code read cycles. Data pins float
to high-impedance when the chip is deselected or outputs are disabled. Data is
internally latched during a write cycle.
CHIP ENABLE : Activates the device’s control logic, input buffers, decoders and sense
amplifiers. CE#-high deselects the device and reduces power consumption to standby
levels.
RESET/DEEP POWER-DOWN : Puts the device in deep power-down mode and resets
internal automation. RP#-high enables normal operation. When driven low, RP# inhibits
write operations which provide data protection during power transitions. Exit from deep
power-down sets the device to read array mode. With RP# = V
write can operate to all blocks without WP# state. Block erase or word write with V
RP# < VHH produce spurious results and should not be attempted.
WRITE ENABLE : Controls writes to the CUI and array blocks. Addresses and data are
latched on the rising edge of the WE# pulse.
WRITE PROTECT : Master control for boot blocks locking. When V
blocks cannot be erased and programmed.
READY/BUSY : Indicates the status of the internal WSM. When low, the WSM is
performing an internal operation (block erase or word write). RY/BY#-high indicates that
the WSM is ready for new commands, block erase is suspended, and word write is
inactive, word write is suspended, or the device is in deep power-down mode. RY/BY#
is always active and does not float when the chip is deselected or data outputs are
disabled.
BLOCK ERASE AND WORD WRITE POWER SUPPLY : For erasing array blocks or
writing words. With V
word write with an invalid V
PP ≤ VPPLK, memory contents cannot be altered. Block erase and
PP (see Section 6.2.3 "DC CHARACTERISTICS") produce
spurious results and should not be attempted.
DEVICE POWER SUPPLY : Internal detection configures the device for 2.7 V, 3.3 V or
5 V operation. To switch from one voltage to another, ramp V
CC down to GND and then
ramp VCC to the new voltage. Do not float any power pins. With VCC ≤ VLKO, all write
attempts to the flash memory are inhibited. Device operations at invalid V
(see Section 6.2.3 "DC CHARACTERISTICS") produce spurious results and should
not be attempted.
HH, block erase or word
IH <
IL, locked boot
CC voltage
- 4 -
1 INTRODUCTION
This datasheet contains LH28F800BG-L/BGH-L
specifications. Section 1 provides a flash memory
overview. Sections 2, 3, 4 and 5 describe the
memory organization and functionality. Section 6
covers electrical specifications. LH28F800BG-L/
BGH-L flash memories documentation also includes
ordering information which is referenced in
Section 7.
1.1New Features
Key enhancements of LH28F800BG-L/BGH-L
SmartVoltage flash memories are :
• SmartVoltage Technology
• Enhanced Suspend Capabilities
• Boot Block Architecture
Note following important differences :
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
But, 5 V V
performance. V
eliminates the need for a separate 12 V converter,
PP = 12 V maximizes block erase and word
while V
write performance. In addition to flexible erase and
program voltages, the dedicated V
complete data protection when V
Table 1 VCC and VPP Voltage Combinations
VCC VOLTAGEVPP VOLTAGE
Internal VCC and VPP detection circuitry automatically configures the device for optimized read
and write operations.
CC provides the highest read
PP at 2.7 V, 3.3 V and 5 V
PP pin gives
PP ≤ VPPLK.
Offered by SmartVoltage Technology
2.7 V2.7 V, 3.3 V, 5 V, 12 V
3.3 V3.3 V, 5 V, 12 V
5 V5 V, 12 V
PPLK has been lowered to 1.5 V to support
•V
2.7 V, 3.3 V and 5 V block erase and word
write operations. Designs that switch V
PP off
during read operations should make sure that
PP voltage transitions to GND.
the V
• To take advantage of SmartVoltage technology,
allow V
PP connection to 2.7 V, 3.3 V or 5 V.
1.2Product Overview
The LH28F800BG-L/BGH-L are high-performance
8 M-bit SmartVoltage flash memories organized as
512 k-word of 16 bits. The 512 k-word of data is
arranged in two 4 k-word boot blocks, six 4 k-word
parameter blocks and fifteen 32 k-word main blocks
which are individually erasable in-system. The
memory map is shown in Fig. 1.
SmartVoltage technology provides a choice of V
and VPP combinations, as shown in Table 1, to
meet system performance and power expectations.
2.7 V V
power of 5 V V
CC consumes approximately one-fifth the
CC and 3.3 V VCC consumes
approximately one-fourth the power of 5 V V
CC
CC.
A Command User Interface (CUI) serves as the
interface between the system processor and
internal operation of the device. A valid command
sequence written to the CUI initiates device
automation. An internal Write State Machine (WSM)
automatically executes the algorithms and timings
necessary for block erase and word write
operations.
A block erase operation erases one of the device’s
32 k-word blocks typically within 0.39 second (5 V
V
CC, 12 V VPP), 4 k-word blocks typically within
0.25 second (5 V V
CC, 12 V VPP) independent of
other blocks. Each block can be independently
erased 100 000 times. Block erase suspend mode
allows system software to suspend block erase to
read data from, or write data to any other block.
Writing memory data is performed in word
increments of the device’s 32 k-word blocks
typically within 8.4 µs (5 V V
word blocks typically within 17 µs (5 V V
PP). Word write suspend mode enables the
V
CC, 12 V VPP), 4 k-
CC, 12 V
- 5 -
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
system to read data from, or write to any other
flash memory array location.
The boot block is located at either the top or the
bottom of the address map in order to
accommodate different micro-processor protect for
boot code location. The hardware-lockable boot
block provides complete code security for the
kernel code required for system initialization.
Locking and unlocking of the boot block is
controlled by WP# and/or RP# (see Section 4.9 for
details). Block erase or word write for boot block
must not be carried out by WP# to low and RP# to
IH.
V
The status register indicates when the WSM’s block
erase or word write operation is finished.
The RY/BY# output gives an additional indicator of
WSM activity by providing both a hardware signal
of status (versus software polling) and status
masking (interrupt masking for background block
erase, for example). Status polling using RY/BY#
minimizes both CPU overhead and system power
consumption. When low, RY/BY# indicates that the
WSM is performing a block erase or word write.
RY/BY#-high indicates that the WSM is ready for a
new command, block erase is suspended (and
word write is inactive), word write is suspended, or
the device is in deep power-down mode.
The access time is 85 ns (t
AVQV) at the VCC supply
voltage range of 4.75 to 5.25 V over the
temperature range, 0 to +70°C (LH28F800BG-L)/
– 40 to +85°C (LH28F800BGH-L). At 4.5 to 5.5 V
V
CC, the access time is 90 ns or 120 ns. At lower
CC voltage, the access time is 100 ns or 130 ns
V
(3.0 to 3.6 V) and 120 ns or 150 ns (2.7 to 3.6 V).
The Automatic Power Saving (APS) feature
substantially reduces active current when the
device is in static mode (addresses not switching).
In APS mode, the typical I
CC and 3 mA at 2.7 V and 3.3 V VCC.
5 V V
When CE# and RP# pins are at V
CCR current is 1 mA at
CC, the ICC
CMOS standby mode is enabled. When the RP#
pin is at GND, deep power-down mode is enabled
which minimizes power consumption and provides
write protection during reset. A reset time (t
PHQV) is
required from RP# switching high until outputs are
valid. Likewise, the device has a wake time (t
PHEL)
from RP#-high until writes to the CUI are
recognized. With RP# at GND, the WSM is reset
and the status register is cleared.
The LH28F800BG-L/BGH-L SmartVoltage flash
memories include an on-chip WSM to manage
block erase and word write functions. It allows for :
100% TTL-level control inputs, fixed power supplies
during block erasure and word write, and minimal
processor overhead with RAM-like interface timings.
After initial device power-up or return from deep
power-down mode (see Table 2 "Bus Operations"),
the device defaults to read array mode.
Manipulation of external memory control pins allow
array read, standby and output disable operations.
Status register and identifier codes can be
accessed through the CUI independent of the V
voltage. High voltage on VPP enables successful
block erasure and word writing. All functions
associated with altering memory contents—block
erase, word write, status and identifier codes—are
accessed via the CUI and verified through the
status register.
Commands are written using standard microprocessor write timings. The CUI contents serve as
input to the WSM, which controls the block erase
and word write. The internal algorithms are
regulated by the WSM, including pulse repetition,
internal verification and margining of data.
Addresses and data are internally latched during
write cycles. Writing the appropriate command
outputs array data, accesses the identifier codes or
outputs status register data.
PP
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
software to suspend a word write to read data from
any other flash memory array location.
2.1Data Protection
Depending on the application, the system designer
may choose to make the V
PP power supply
switchable (available only when memory block
erases or word writes are required) or hardwired to
PPH1/2/3. The device accommodates either design
V
practice and encourages optimization of the
processor-memory interface.
When V
PP ≤ VPPLK, memory contents cannot be
altered. The CUI, with two-step block erase or word
write command sequences, provides protection
from unwanted operations even when high voltage
is applied to V
when V
CC is below the write lockout voltage VLKO
PP. All write functions are disabled
or when RP# is at VIL. The device’s boot blocks
locking capability for WP# provides additional
protection from inadvertent code or data alteration
by block erase and word write operations.
3 BUS OPERATION
The local CPU reads and writes flash memory insystem. All bus cycles to or from the flash memory
conform to standard microprocessor bus cycles.
3.1Read
Information can be read from any block, identifier
codes or status register independent of the V
voltage. RP# can be at either VIH or VHH.
PP
Interface software that initiates and polls progress
of block erase and word write can be stored in any
block. This code is copied to and executed from
system RAM during flash memory updates. After
successful completion, reads are again possible via
the Read Array command. Block erase suspend
allows system software to suspend a block erase to
read/write data from/to blocks other than that which
is suspended. Word write suspend allows system
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 deep powerdown mode, the device automatically resets to read
array mode. Five control pins dictate the data flow
in and out of the component : CE#, OE#, WE#,
RP# and WP#. CE# and OE# must be driven
active to obtain data at the outputs. CE# is the
- 8 -
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
7FFFF
00002
00001
00000
Reserved for
Future Implementation
Device Code
Manufacture Code
device selection control, and when active enables
the selected memory device. OE# is the data
output (DQ
0-DQ15) control and when active drives
the selected memory data onto the I/O bus. WE#
must be at V
IH and RP# must be at VIH or VHH.
Fig. 11 illustrates read cycle.
3.2Output Disable
With OE# at a logic-high level (VIH), the device
outputs are disabled. Output pins (DQ
0-DQ15) are
placed in a high-impedance state.
3.3Standby
CE# at a logic-high level (VIH) places the device in
standby mode which substantially reduces device
power consumption. DQ
0-DQ15 outputs are placed
in a high-impedance state independent of OE#. If
deselected during block erase or word write, the
device continues functioning, and consuming active
power until the operation completes.
3.4Deep Power-Down
RP# at VIL initiates the deep power-down mode.
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 or
word write 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.
3.5Read Identifier Codes Operation
The read identifier codes operation outputs the
manufacture code and device code (see Fig. 2).
Using the manufacture and device codes, the
system CPU can automatically match the device
with its proper algorithms.
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 100 ns. Time t
PHQV is required
after return from power-down 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 or word write 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
after RP# goes to logic-high (V
command can be written.
As with any automated device, it is important to
PHWL is required
IH) before another
Fig. 2 Device Identifier Code Memory Map
3.6Write
Writing commands to the CUI enable reading of
device data and identifier codes. They also control
inspection and clearing of the status register. When
V
CC = VCC1/2/3/4 and VPP = VPPH1/2/3, the CUI
additionally controls block erasure and word write.
The Block Erase command requires appropriate
command data and an address within the block to
be erased. The Word Write command requires the
command and address of the location to be written.
- 9 -
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
The CUI does not occupy an addressable memory
location. It is written when WE# and CE# are
active. The address and data needed to execute a
command are latched on the rising edge of WE# or
CE# (whichever goes high first). Standard
4 COMMAND DEFINITIONS
When the VPP voltage ≤ VPPLK, read operations
from the status register, identifier codes, or blocks
are enabled. Placing V
successful block erase and word write operations.
PPH1/2/3 on VPP enables
microprocessor write timings are used. Fig. 12 and
Fig. 13 illustrate WE# and CE# controlled write
operations.
Device operations are selected by writing specific
commands into the CUI. Table 3 defines these
commands.
Table 2 Bus Operations
MODENOTERP#CE#OE#WE#
Read1, 2, 3, 8
Output Disable3
Standby3
VIHor V
VIHor V
VIHor V
HH
HH
HH
V
IL
V
IL
V
IH
V
IL
V
IH
XXXXHigh ZX
V
V
IH
IH
ADDRESS
XXD
VPPDQ0-15 RY/BY#
OUT
XXHigh ZX
Deep Power-Down4VILXXXXXHigh ZV
Read Identifier Codes8
Write3, 6, 7, 8
VIHor V
VIHor V
HH
HH
V
IL
V
IL
V
IL
V
IH
V
V
IH
IL
See Fig. 2
X(
NOTE 5)
XXDINX
NOTES :
1. Refer to Section 6.2.3 "DC CHARACTERISTICS".
When V
PP ≤ VPPLK, memory contents can be read, but
not altered.
2. X can be V
PPLK or VPPH1/2/3 for VPP. See Section 6.2.3 "DC
V
CHARACTERISTICS" for V
3. RY/BY# is V
block erase or word write algorithms. It is V
when the WSM is not busy, in block erase suspend
mode (with word write inactive), word write suspend
mode or deep power-down mode.
IL or VIH for control pins and addresses, and
PPLK and VPPH1/2/3 voltages.
OL when the WSM is executing internal
OH during
4. RP# at GND±0.2 V ensures the lowest deep powerdown current.
5. See Section 4.2 for read identifier code data.
6. Command writes involving block erase or word write are
reliably executed when V
V
CC1/2/3/4. Block erase or word write with VIH < RP# <
HH produce spurious results and should not be
V
attempted.
7. Refer to Table 3 for valid D
8. Don’t use the timing both OE# and WE# are V
PP = VPPH1/2/3 and VCC =
IN during a write operation.
X
OH
V
OH
IL.
- 10 -
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
COMMAND
Table 3 Command Definitions
BUS CYCLES
REQ’D.
NOTE
FIRST BUS CYCLESECOND BUS CYCLE
(NOTE 1)
Oper
Addr
(NOTE 7)
(NOTE 2)
Data
(NOTE 3)
Oper
(NOTE 1)
Addr
(NOTE 2)
Data
Read Array/Reset1WriteXFFH
Read Identifier Codes≥ 24WriteX90HReadIAID
Read Status Register2WriteX70HReadXSRD
Clear Status Register1WriteX50H
Block Erase25WriteBA20HWriteBAD0H
Word Write25, 6WriteWA
Block Erase and
Word Write Suspend
Block Erase and
Word Write Resume
15WriteXB0H
15WriteXD0H
40H or 10H
WriteWAWD
NOTES :
1. Bus operations are defined in Table 2.
2. X = Any valid address within the device.
IA = Identifier code address : see Fig. 2.
BA = Address within the block being erased.
WA = Address of memory location to be written.
3. SRD = Data read from status register. See Table 6 for a
description of the status register bits.
WD = Data to be written at location WA. Data is latched
on the rising edge of WE# or CE# (whichever
goes high first).
ID = Data read from identifier codes.
4. Following the Read Identifier Codes command, read
operations access manufacture and device codes. See
Section 4.2 for read identifier code data.
5. If the block is boot block, WP# must be at V
must be at V
operations. Attempts to issue a block erase or word write
to a boot block while WP# is V
6. Either 40H or 10H is recognized by the WSM as the
word write setup.
7. Commands other than those shown above are reserved
by SHARP for future device implementations and should
not be used.
HH to enable block erase or word write
IH or RP# is VIH.
IH or RP#
(NOTE 3)
- 11 -
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
4.1Read Array Command
Upon initial device power-up and after exit from
deep power-down mode, the device defaults to
read array mode. This operation is also initiated by
writing the Read Array command. The device
remains enabled for reads until another command
is written. Once the internal WSM has started a
block erase or word write, the device will not
recognize the Read Array command until the WSM
completes its operation unless the WSM is
suspended via an Erase Suspend or Word Write
Suspend command. The Read Array command
functions independently of the V
RP# can be V
IH or VHH.
PP voltage and
4.2Read Identifier Codes Command
The identifier code operation is initiated by writing
the Read Identifier Codes command. Following the
command write, read cycles from addresses shown
in Fig. 2 retrieve the manufacture and device codes
(see Table 4 for identifier code values). To
terminate the operation, write another valid
command. Like the Read Array command, the
Read Identifier Codes command functions
independently of the V
The status register may be read to determine when
a block erase or word write is complete and
whether the operation completed successfully. It
may be read at any time by writing the Read Status
Register command. After writing this command, all
subsequent read operations output data from the
status register until another valid command is
written. The status register contents are latched on
the falling edge of OE# or CE#, whichever occurs.
OE# or CE# must toggle to V
IH before further reads
to update the status register latch. The Read Status
Register command functions independently of the
V
PP voltage. RP# can be VIH or VHH.
4.4Clear Status Register Command
Status register bits SR.5, SR.4, SR.3 or SR.1 are
set to "1"s by the WSM and can only be reset by
the Clear Status Register command. These bits
indicate various failure conditions (see Table 6). By
allowing system software to reset these bits,
several operations (such as cumulatively erasing
multiple blocks or writing several words in
sequence) may be performed. The status register
may be polled to determine if an error occurred
during the sequence.
To clear the status register, the Clear Status
Register command (50H) is written. It functions
independently of the applied V
be V
IH or VHH. This command is not functional
PP voltage. RP# can
during block erase or word write suspend modes.
4.5Block Erase Command
Erase is executed one block at a time and initiated
by a two-cycle command. A block erase setup is
first written, followed by a block erase confirm.
This command sequence requires appropriate
sequencing and an address within the block to be
erased (erase changes all block data to FFFFH).
Block preconditioning, erase, and verify are handled
internally by the WSM (invisible to the system).
After the two-cycle block erase sequence is written,
the device automatically outputs status register data
when read (see Fig. 3). The CPU can detect block
erase completion by analyzing the output data of
the RY/BY# pin or status register bit SR.7.
When the block erase is complete, status register
bit SR.5 should be checked. If a block erase error
is detected, the status register should be cleared
before system software attempts corrective actions.
- 12 -
LH28F800BG-L/BGH-L (FOR TSOP, CSP)
The CUI remains in read status register mode until
a new command is issued.
This two-step command sequence of set-up
followed by execution ensures that block contents
are not accidentally erased. An invalid Block Erase
command sequence will result in both status
register bits SR.4 and SR.5 being set to "1". Also,
reliable block erasure can only occur when V
CC1/2/3/4 and VPP = VPPH1/2/3. In the absence of
V
CC =
this high voltage, block contents are protected
against erasure. If block erase is attempted while
PP ≤ VPPLK, SR.3 and SR.5 will be set to "1".
V
Successful block erase for boot blocks requires that
the corresponding if set, that WP# = V
V
HH. If block erase is attempted to boot block when
the corresponding WP# = V
IL or RP# = VIH, SR.1
IH or RP# =
and SR.5 will be set to "1". Block erase operations
IH < RP# < VHH produce spurious results and
with V
should not be attempted.
4.6Word Write Command
Word write is executed by a two-cycle command
sequence. Word write setup (standard 40H or
alternate 10H) is written, followed by a second write
that specifies the address and data (latched on the
rising edge of WE#). The WSM then takes over,
controlling the word write and write verify algorithms
internally. After the word write sequence is written,
the device automatically outputs status register data
when read (see Fig. 4). The CPU can detect the
completion of the word write event by analyzing the
RY/BY# pin or status register bit SR.7.
When word write is complete, status register bit
SR.4 should be checked. If word write error is
detected, the status register should be cleared. The
internal WSM verify only detects errors for "1"s that
do not successfully write to "0"s. The CUI remains
in read status register mode until it receives another
command.
Reliable word writes can only occur when V
CC1/2/3/4 and VPP = VPPH1/2/3. In the absence of
V
CC =
this high voltage, memory contents are protected
against word writes. If word write is attempted while
V
PP ≤ VPPLK, status register bits SR.3 and SR.4 will
be set to "1". Successful word write for boot blocks
requires that the corresponding if set, that WP# =
IH or RP# = VHH. If word write is attempted to
V
boot block when the corresponding WP# = V
RP# = V
write operations with V
IH, SR.1 and SR.4 will be set to "1". Word
IH < RP# < VHH produce
IL or
spurious results and should not be attempted.
4.7Block Erase Suspend Command
The Block Erase Suspend command allows block
erase interruption to read or word write data in
another block of memory. Once the block erase
process starts, writing the Block Erase Suspend
command requests that the WSM suspend the
block erase sequence at a predetermined point in
the algorithm. The device outputs status register
data when read after the Block Erase Suspend
command is written. Polling status register bits
SR.7 and SR.6 can determine when the block
erase operation has been suspended (both will be
set to "1"). RY/BY# will also transition to V
Specification t
WHRH2 defines the block erase
suspend latency.
At this point, a Read Array command can be
written to read data from blocks other than that
which is suspended. A Word Write command
sequence can also be issued during erase suspend
to program data in other blocks. Using the Word
Write Suspend command (see Section 4.8), a
word write operation can also be suspended.
During a word write operation with block erase
suspended, status register bit SR.7 will return to "0"
and the RY/BY# output will transition to V
However, SR.6 will remain "1" to indicate block
erase suspend status.
OH.
OL.
- 13 -
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