W29GL256SH9T-TR Datasheet, PDF (16/88 Pages) Winbond – 256M-BIT 3.0-VOLT PARALLEL FLASH MEMORY WITH PAGE MODE

W29GL256S
future use. Read access is possible outside of an MMO address map and will return non-valid
(undefined) data.
What appears in the flash device address space at any given time is one of four address map modes:
 Read Mode
 Memory Map Overlay (MMO) Mode
 Status Register (SR) Mode
 Data Polling Mode
In Read Mode the entire Flash Memory Array may be directly read. Read mode is entered during
Power Up, after a Hardware Reset, Command Reset completion, or when an internal algorithm is
suspended, all of which is controlled by the Write State Controller. While in the Read Mode,
command accesses are permitted when an internal algorithm is suspended. There are subsets of
commands that will be accepted in Read Mode while an Internal Algorithm is suspended.
The Status Register read command can be issued in any mode. This execution will cause the MMO
of the Status Register to appear in the device address space at every word address location. To do
this, the device interface waits for a read access, ignoring any write access. The content of the Status
Register is presented at the next read access, after which it exits the Status Register MMO, and
returns to the previous mode in which the Status Register read command was received.
While the Write State Controller is performing an internal algorithm, such as a non-volatile memory
array program or an erase operation, none of the Main Memory Array is accessible because, the
entire flash device address space is replaced by the MMO of the Data Polling Status at every word
location in the device address space.
While in an internal algorithm operation, only the Status Register Read command or a Program /
Erase suspend command will be accepted, ignoring all other commands. Hence, no other MMO may
be entered.
The Data Polling MMO is visible during an internal algorithm operation and once a suspend command
has been executed it is present up to the moment the device suspends the internal algorithm. When
the internal algorithm is suspended the Data Polling MMO is exited and the Main Memory Array data
is available again. The Data Polling MMO is activated again when the suspended internal algorithm
operation is resumed. At the completion of an internal algorithm operation, the Data Polling MMO is
exited and the device goes back to operation from which it was called.
Publication Release Date: Jul 02, 2014
Revision C
16