ESMT
F49L160UA/F49L160BA
Output Enable (
) is asserted low. Refer to Figure
OE
RY/BY :
21, Data Polling Timings (During Embedded
Algorithms), Figure 19 shows the Data Polling
algorithm.
Ready/Busy
The RY/
is a dedicated, open-drain output pin that
BY
indicates whether an Embedded Algorithm is in
progress or complete. The RY/ status is valid after
DQ6:Toggle BIT I
BY
pulse in the command
Toggle Bit I on DQ6 indicates whether an Embedded
Program or Erase algorithm is in progress or complete,
or whether the device has entered the Erase Suspend
mode. Toggle Bit I may be read at any address, and is
the rising edge of the final
WE
is an open-drain output,
sequence. Since RY/
BY
pins can be tied together in parallel
several RY/
BY
with a pull-up resistor to V
.
CC
valid after the rising edge of the final
pulse in the
WE
command sequence (prior to the program or erase
operation), and during the sector erase time-out.
If the output is low (Busy), the device is actively erasing
or programming. (This includes programming in the
Erase Suspend mode.) If the output is high (Ready),
the device is ready to read array data (including during
the Erase Suspend mode), or is in the standby mode.
During an Embedded Program or Erase algorithm
operation, successive read cycles to any address
cause DQ6 to toggle. The system may use either
OE
to control the read cycles. When the operation
Table 7 shows the outputs for RY/
.
BY
or
CE
is complete, DQ6 stops toggling.
DQ7: Data Polling
When an erase command sequence is written, if all
sectors selected for erasing are protected, DQ6
toggles for approximately 100 µs, then returns to
reading array data. If not all selected sectors are
protected, the Embedded Erase algorithm erases the
unprotected sectors, and ignores the selected sectors
that are protected.
The DQ7 indicates to the host system whether an
Embedded Algorithm is in progress or completed, or
whether the device is in Erase Suspend mode. The
Data Polling is valid after the rising edge of the final
pulse in the program or erase command
WE
sequence.
The system can use DQ6 and DQ2 together to
determine whether a sector is actively erasing or is
erase-suspended. When the device is actively erasing
(i.e. the Embedded Erase algorithm is in progress),
DQ6 toggles. When the device enters the Erase
Suspend mode, DQ6 stops toggling. However, the
system must also use DQ2 to determine which sectors
are erasing or erase-suspended. Alternatively, the
system can use DQ7.
During the Embedded Program algorithm, the device
outputs on DQ7 the complement of the datum
programmed
to DQ7. This DQ7 status also applies to programming
during Erase Suspend. When the Embedded Program
algorithm is complete, the device outputs the true data
on DQ7. The system must provide the program address
to read valid status information on DQ7. If a program
address falls within a protected sector, Data Polling on
DQ7 is active for approximately 1 µs, then the device
returns to reading array data.
If a program address falls within a protected sector,
DQ6 toggles for approximately 2 µs after the program
command sequence is written, then returns to reading
array data.
During the Embedded Erase algorithm, Data Polling
produces a “0” on DQ7. When the Embedded Erase
algorithm is complete, or if the device enters the Erase
Suspend mode, Data Polling produces a “1” on DQ7.
The system must provide an address within any of the
sectors selected for erasure to read valid status
information on DQ7.
DQ6 also toggles during the erase-suspend-program
mode, and stops toggling once the Embedded
Program algorithm is complete. Table 7 shows the
outputs for Toggle Bit I on DQ6. Figure 20 shows the
toggle bit algorithm. Figure 22 shows the toggle bit
timing diagrams. Figure 25 shows the differences
between DQ2 and DQ6 in graphical form. Refer to the
subsection on DQ2: Toggle Bit II.
After an erase command sequence is written, if all
sectors selected for erasing are protected, Data Polling
on DQ7 is active for approximately 100 µs, then the
device returns to reading array data. If not all selected
sectors are protected, the Embedded Erase algorithm
erases the unprotected sectors, and ignores the
selected sectors that are protected.
DQ2: Toggle Bit II
The “Toggle Bit II” on DQ2, when used with DQ6,
indicates whether a particular sector is actively erasing
(that is, the Embedded Erase algorithm is in progress),
or whether that sector is erase-suspended. Toggle Bit II
When the system detects DQ7 has changed from the
complement to true data, it can read valid data at DQ7~
DQ0 on the following read cycles. This is because DQ7
may change asynchronously with DQ0–DQ6 while
is valid after the rising edge of the final WE or CE ,
whichever happens first, in the command sequence.
Elite Semiconductor Memory Technology Inc.
Publication Date : Dec. 2006
Revision: 1.3
16/51
ESMT [ ELITE SEMICONDUCTOR MEMORY TECHNOLOGY INC. ]
