MBM29LV400TC-55PF Meet Spansion Inc., MBM29LV400TC-55PF Datasheet - Page 18

• Manufacturer Part Number: MBM29LV400TC-55PF
• Description: Flash Memory Cmos 4m 512k ? 8/256k ? 16 Bit
• Manufacturer: Meet Spansion Inc.

1. Read/Reset Command
2. Autoselect Command
3. Byte/Word Programming
COMMAND DEFINITIONS
Device operations are selected by writing specific address and data sequences into the command register.
Writing incorrect address and data values or writing them in the improper sequence will reset the devices to the
read mode. “MBM29LV400TC/400BC Standard Command Definitions Table” in DEVICE BUS OPERATIONS
defines the 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
Characteristics 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
programmers typically access the signature codes by raising A
voltage onto the address lines is not generally desired system design practice.
The device contains an Autoselect command operation to supplement traditional PROM programming
methodology. 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 (MBM29LV400TC = B9h and
MBM29LV400BC = BAh for 8 mode; MBM29LV400TC = 22B9h and MBM29LV400BC = 22BAh for 16 mode).
(See “MBM29LV400TC/400BC Sector Protection Verify Autoselect Codes Table” and “Extended Autoselect Code
Table” in DEVICE BUS OPERATIONS.) All manufacturer and device codes will exhibit odd parity with DQ
defined as the parity
bit. Sector state (protection or unprotection) will be informed by address XX02h for 16 (XX04h for 8).
Scanning the sector addresses (A
“1” at device output DQ
on the protected sector. (See “MBM29LV400TC/400BC User Bus Operations Tables (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.
IH
)” in DEVICE BUS OPERATIONS.)
0
to DQ
MBM29LV400TC
7
and DQ
8
0
to DQ
for a protected sector. The programming verification should be perform margin mode
15
bits are ignored.
17
, A
16
, A
15
, A
14
, A
-55/70/90
13
, and A
12
/MBM29LV400BC
) while (A
9
to a high voltage. However, multiplexing high
6
5
, A
= 1) to read/reset mode, the read/reset
1
, A
0
) = (0, 1, 0) will produce a logical
IH
and BYTE =
-55/70/90
7
17