MT28F008B5 Micron Technology, MT28F008B5 Datasheet - Page 9

• Manufacturer Part Number: MT28F008B5
• Description: (MT28F008B5 / MT28F800B5) FLASH MEMORY
• Manufacturer: Micron Technology

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DataSheet
Parameter Blocks
and more frequently changing system parameters and
also may store configuration or diagnostic coding.
These blocks are enabled for erasure when the V
is at V
required.
Main Memory Blocks
memory blocks and do not require a super-voltage on
RP# or WP# control to be erased or written. These
blocks are intended for code storage, ROM-resident
applications or operating systems that require in-sys-
tem update capability.
OUTPUT (READ) OPERATIONS
different types of READs. Depending on the current
mode of the device, a READ operation produces data
from the memory array, status register or device iden-
tification register. In each of these three cases, the
WE#, CE# and OE# inputs are controlled in a similar
manner. Moving between modes to perform a specific
READ is described in the Command Execution section.
Memory Array
OE# and CE# must be LOW. Valid data is output on the
DQ pins when these conditions are met, and a valid
address is given. Valid data remains on the DQ pins
until the address changes, or OE# or CE# goes HIGH,
whichever occurs first. The DQ pins continue to out-
put new data after each address transition as long as
OE# and CE# remain LOW.
When the memory array is accessed as a 512K x 16,
BYTE# is HIGH, and data is output on DQ0–DQ15. To
access the memory array as a 1 Meg x 8, BYTE# must
be LOW, DQ8–DQ14 are High-Z, and all data is output
on DQ0–DQ7. The DQ15/(A-1) pin becomes the lowest
order address input so that 1,048,576 locations can be
read.
cally in the array read mode. All commands and their
operations are described in the Command Set and
Command Execution sections.
8Mb Smart 5 Boot Block Flash Memory
MT28F800B5_3.fm - Rev. 3, Pub. 8/2002
4
U
The two 8KB parameter blocks store less sensitive
The eight remaining blocks are general-purpose
The MT28F800B5 and MT28F008B5 feature three
To read the memory array, WE# must be HIGH, and
The MT28F800B5 features selectable bus widths.
After power-up or RESET, the device is automati-
.com
PPH
. No super-voltage unlock or WP# control is
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PP
SMART 5 BOOT BLOCK FLASH MEMORY
pin
Status Register
the same input sequencing as a READ of the array
except that the address inputs are “Don’t Care.” The
status register contents are always output on DQ0–
DQ7, regardless of the condition of BYTE# on the
MT28F800B5. DQ8–DQ15 are LOW when BYTE# is
HIGH, and DQ8–DQ14 are High-Z when BYTE# is
LOW. Data from the status register is latched on the
falling edge of OE# or CE#, whichever occurs last. If the
contents of the status register change during a read of
the status register, either OE# or CE# may be toggled
while the other is held LOW to update the output.
cally enters the status register read mode. In addition,
a READ during a WRITE or ERASE produces the status
register contents on DQ0–DQ7. When the device is in
the erase suspend mode, a READ operation produces
the status register contents until another command is
issued. In certain other modes, READ STATUS REGIS-
TER may be given to return to the status register read
mode. All commands and their operations are
described in the Command Set and Command Execu-
tion sections.
Identification Register
ters requires the same input sequencing as a READ of
the array. WE# must be HIGH, and OE# and CE# must
be LOW. However, ID register data is output only on
DQ0–DQ7, regardless of the condition of BYTE# on the
MT28F800B5. A0 is used to decode between the two
bytes of the device ID register; all other address inputs
are “Don’t Care.” When A0 is LOW, the manufacturer
compatibility ID is output, and when A0 is HIGH, the
device ID is output. DQ8–DQ15 are High-Z when
BYTE# is LOW. When BYTE# is HIGH, DQ8–DQ15 are
00h when the manufacturer compatibility ID is read
and 88h when the device ID is read.
READ IDENTIFICATION may be issued while the
device is in certain other modes. In addition, the iden-
tification register read mode can be reached by apply-
ing a super-voltage (V
method, the ID register can be read while the device is
in any mode. When A9 is returned to V
device will return to the previous mode.
Performing a READ of the status register requires
Following a WRITE or ERASE, the device automati-
A READ of the two 8-bit device identification regis-
To get to the identification register read mode,
9
Micron Technology, Inc. Reserves the right to change products or specifications without notice.
ID
) to the A9 pin. Using this
©2002, Micron Technology Inc.
IL
or V
8Mb
IH
, the