MBM29SL800BD Fujitsu Media Devices, MBM29SL800BD Datasheet - Page 16

• Manufacturer Part Number: MBM29SL800BD
• Description: (MBM29SL800TD/BD) FLASH MEMORY CMOS 8 M (1 M X 8/512 K X 16) BIT
• Manufacturer: Fujitsu Media Devices

16
MBM29SL800TD
Read/Reset Command
Autoselect Command
Byte/Word Programming
COMMAND DEFINITIONS
Device operations are selected by writing specific address and data sequences into the command register.
“MBM29SL800TD/800BD Standard Command Definitions Table” in
valid register command sequences. Note that the Erase Suspend (B0h) and Erase Resume (30h) commands
are valid only while the Sector Erase operation is in progress. Moreover both Read/Reset commands are
functionally equivalent, resetting the device to the read mode. Please note that commands are always written
at DQ
In order to return from Autoselect mode or Exceeded Timing Limits (DQ
operation is initiated by writing the Read/Reset command sequence into the command register. Microprocessor
read cycles retrieve array data from the memory. The devices remain enabled for reads until the command
register contents are altered.
The devices will automatically power-up in the read/reset state. In this case, a command sequence is not required
to read data. Standard microprocessor read cycles will retrieve array data. This default value ensures that no
spurious alteration of the memory content occurs during the power transition. Refer to the AC Read Character-
istics and Waveforms for the specific timing parameters.
Flash memories are intended for use in applications where the local CPU alters memory contents. As such,
manufacture and device codes must be accessible while the devices reside in the target system. PROM pro-
grammers typically access the signature codes by raising A
onto the address lines is not generally desired system design practice.
The device contains an Autoselect command operation to supplement traditional PROM programming method-
ology. The operation is initiated by writing the Autoselect command sequence into the command register.
Following the command write, a read cycle from address XX00h retrieves the manufacture code of 04h. A read
cycle from address XX01h for 16 (XX02h for 8) returns the device code (MBM29SL800TD
MBM29SL800BD
mode) . (See “MBM29SL800TD/800BD Sector Protection Verify Autoselect Codes Table and Extended
Autoselect Code Table in
parity with DQ
XX02h for 16 (XX04h for 8) .
Scanning the sector addresses (A
logical “1” at device output DQ
mode on the protected sector. (See “MBM29SL800TD/800BD User Bus Operations Table (BYTE = V
= V
To terminate the operation, it is necessary to write the Read/Reset command sequence into the register, and
also to write the Autoselect command during the operation, execute it after writing Read/Reset command
sequence.
The devices are programmed on a byte-by-byte (or word-by-word) basis. Programming is a four bus cycle
operation. There are two “unlock” write cycles. These are followed by the program set-up command and data
write cycles. Addresses are latched on the falling edge of CE or WE, whichever happens later and the data is
latched on the rising edge of CE or WE, whichever happens first. The rising edge of CE or WE (whichever
happens first) begins programming. Upon executing the Embedded Program Algorithm command sequence,
the system is not required to provide further controls or timings. The device will automatically provide adequate
internally generated program pulses and verify the programmed cell margin.
The automatic programming operation is completed when the data on DQ
bit at which time the devices return to the read mode and addresses are no longer latched. (See “Hardware
Sequence Flags Table”.) Therefore, the devices require that a valid address to the devices be supplied by the
IL
)” in DEVICE BUS OPERATION.)
0
to DQ
7
7
and DQ
defined as the parity bit. Sector state (protection or unprotection) will be informed by address
6Bh for 8 mode; MBM29SL800TD
8
to DQ
DEVICE BUS OPERATION”.) All manufacturer and device codes will exhibit odd
15
0
for a protected sector. The programming verification should be perform margin
bits are ignored.
-10/12
18
, A
17
, A
/MBM29SL800BD
16
, A
15
, A
14
, A
13
, and A
9
22EAh and MBM29SL800BD
to a high voltage. However, multiplexing high voltage
12
) while (A
DEVICE BUS OPERATION defines the
5
1) to read/reset mode, the read/reset
7
6
is equivalent to data written to this
, A
1
, A
-10/12
0
)
(0, 1, 0) will produce a
226Bh for 16
IH
and BYTE
EAh and