MBM29LV160TM-BM90 Meet Spansion Inc., MBM29LV160TM-BM90 Datasheet - Page 21

• Manufacturer Part Number: MBM29LV160TM-BM90
• Description: Flash Memory Cmos 16 M 2m ? 8/1m ? 16 Bit Mirrorflashtm*
• Manufacturer: Meet Spansion Inc.

■ COMMAND DEFINITIONS
Reset Command
Autoselect Command
Programming
Device operations are selected by writing specific address and data sequences into the command register.
“MBM29LV160TM/BM Standard Command Definitions” in ■DEVICE BUS OPERATION shows 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. Also the Program Suspend (B0h) and Program Resume (30h)
commands are valid only while the Program operation is in progress.Moreover Reset commands are functionally
equivalent, resetting the device to the read mode. Please note that commands must be asserted to DQ
and DQ
In order to return from Autoselect mode or Exceeded Timing Limits (DQ
is initiated by writing the Reset command sequence into the command register. The devices remain enabled for
reads until the command register contents are altered.
The devices will automatically be in the reset state after power-up. In this case, a command sequence is not
required in order to read data.
Flash memories are intended for use in applications where the local CPU alters memory contents. Therefore,
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.
The Autoselect command sequence is initiated first by writing two unlock cycles. This is followed by a third write
cycle that contains the address and the Autoselect command. Then the manufacture and device codes can be
read from the address, and an actual data of memory cell can be read from the another address.
Following the command write, a read cycle from address 00h returns the manufactures’s code (Fujitsu = 04h).
A read cycle at address 01h outputs device code (MBM29LV160TM : C4h in byte mode and 22C4h in word
mode ; MBM29LV160BM : 49h in byte mode and 2249h in word mode). Refer to “Sector Protection Verify
Autoselect Codes” in ■DEVICE BUS OPERATION.
To terminate the operation, it is necessary to write the Reset command into the register. To execute the Autoselect
command during the operation, Reset command must be written before the Autoselect command.
The devices are programmed on a word-by-word (or byte-by-byte ) basis. Programming is a four bus cycle
operation. There are 2 “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)
starts 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 system can determine the status of the program operation by using DQ
RY/BY. The Data Polling and Toggle Bit are automatically performed at the memory location being programmed.
The programming operation is completed when the data on DQ
the devices return to the read mode and plogram addresses are no longer latched. Therefore, the devices require
that a valid address to the devices be supplied by the system at this particular instance. Hence Data Polling
requires the same address which is being programmed.
If hardware reset occurs during the programming operation, the data being written is not guaranteed.
Programming is allowed in any address sequence and across sector boundaries. Beware that a data “0” cannot
be programmed back to a “1”. Attempting to do so may result in either failure condition or an apparent success
15
to DQ
8
bits are ignored.
Retired Product DS05-20906-4E_July 31, 2007
9
to a high voltage. However applying high voltage
MBM29LV160TM/BM
7
is equivalent to data written to this bit at which
5
= 1) to Read mode, the Reset operation
7
(Data Polling), DQ
6
(Toggle Bit) or
7
to DQ
90
0
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