MBM29DL32XTE/BE80/90
If the software (program code) for Autoselect command is stored into the Flash memory, the device and manu-
facture codes should be read from the other bank where is not contain the software.
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 se-
quence.
• Byte/Word Programming
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 system can determine the status of the program operation by using DQ7 (Data Polling) , DQ6 (Toggle Bit) ,
or RY/BY. The Data Polling and Toggle Bit must be performed at the memory location which is being programmed.
The automatic programming operation is completed when the data on DQ7 is equivalent to data written to this
bit at which time the devices return to the read mode and addresses are no longer latched. (See “Hardware
Sequence Flags” in “■ COMMAND DEFINITIONS”, Hardware Sequence Flags.) Therefore, the devices require
that a valid address to the devices be supplied by the system at this particular instance of time. Hence, Data
Polling must be performed at the memory location which is being programmed.
If hardware reset occurs during the programming operation, it is impossible to guarantee the data are being
written.
Programming is allowed in any sequence and across sector boundaries. Beware that a data “0” cannot be
programmed back to a “1”. Attempting to do so may either hang up the device or result in an apparent success
according to the data polling algorithm but a read from Read/Reset mode will show that the data is still “0”. Only
erase operations can convert “0”s to “1”s.
“Embedded ProgramTM Algorithm” in “■ FLOW CHART” illustrates the Embedded ProgramTM Algorithm using
typical command strings and bus operations.
• Program Suspend/Resume
The Profram Suspend command allows the system to interrupt a program operation so that data can be read
from any address. Writing the Program Suspend command (B0h) during the Embedded Program operation
immediately suspends the programming. The Program Suspend command may also be issued during a pro-
gramming operation while an erase is suspended. The bank addresses of sector being programmed should be
set when writing the Program Suspend command.
When the Program Suspend command is written during a process, the device halts the program operation within
1 µs and updates the state bits.
After the program operation has been suspended, the system can read data from any address. The data at
program-suspended address is not valid. Normal read timing and command definitions apply.
After Program Resume command (30h) is written, the device reverts to programming. The bank address of
sectorsbeingsuspendedshouldbesetwhenwritingtheProgramResume command. Thesystemcandetermine
the program operation status using the DQ7 or DQ6 status bits, just as in the standard program operation. See
“Write Operation Status” for more information.
The system may also write Autoselect command sequence when the device in the Program Suspend mode.
The device allows reading Autoselect codes at the addresses within programming sectors, since the codes are
not stored in the memory. When the device exits form the Autoselect mode, the device reverts to the Program
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SPANSION [ SPANSION ]
