S29PL-N_07 SPANSION [SPANSION], S29PL-N_07 Datasheet - Page 39

• Manufacturer Part Number: S29PL-N_07
• Description: 256/128/128 Mb (16/8/8 M x 16-Bit) CMOS, 3.0 Volt-only Simultaneous Read/Write, Page-Mode Flash Memory
• Manufacturer: SPANSION [SPANSION]

D a t a
S h e e t
( P r e l i m i n a r y )
DQ6: Toggle Bit I
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 can be read at any address in the
same bank, and is valid after the rising edge of the final WE# pulse in the command sequence (prior to the
program or erase operation), and during the sector erase time-out.
During an Embedded Program or Erase algorithm operation, successive read cycles to any address cause
DQ6 to toggle. When the operation is complete, DQ6 stops toggling.
After an erase command sequence is written, if all sectors selected for erasing are protected, DQ6 toggles for
approximately t
(all sectors protected toggle time), then returns to reading array data. If not all selected
ASP
sectors are protected, the Embedded Erase algorithm erases the unprotected sectors, and ignores the
selected sectors that are protected.
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 (that is, 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, see
DQ7: Data# Polling. on page 37
If a program address falls within a protected sector, DQ6 toggles for approximately t
after the program
PAP
command sequence is written, then returns to reading array data.
DQ6 also toggles during the erase-suspend-program mode, and stops toggling once the Embedded Program
Algorithm is complete.
See the following for additional information:
Figure 7.4, Write Operation Status Flowchart on page
38,
Figure 11.14, Toggle Bit Timings (During Embedded Algorithms) on page
64,
Table 7.18, Write Operation
Status on page
40, and
Figure 11.15, DQ2 vs. DQ6 on page
64.
Toggle Bit I on DQ6 requires either OE# or CE# to be de-asserted and reasserted to show the change in
state.
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 is
valid after the rising edge of the final WE# pulse in the command sequence. DQ2 toggles when the system
reads at addresses within those sectors that have been selected for erasure. But DQ2 cannot distinguish
whether the sector is actively erasing or is erase-suspended. DQ6, by comparison, indicates whether the
device is actively erasing, or is in Erase Suspend, but cannot distinguish which sectors are selected for
erasure. Thus, both status bits are required for sector and mode information. Refer to
Table 7.18 on page 40
to compare outputs for DQ2 and DQ6. See the following for additional information:
Figure 7.4, Write
Operation Status Flowchart on page 38
and
Figure 11.14, Toggle Bit Timings (During Embedded Algorithms)
on page
64.
Reading Toggle Bits DQ6/DQ2
Whenever the system initially begins reading toggle bit status, it must read DQ7 – DQ0 at least twice in a row
to determine whether a toggle bit is toggling. Typically, the system would note and store the value of the
toggle bit after the first read. After the second read, the system would compare the new value of the toggle bit
with the first. If the toggle bit is not toggling, the device has completed the program or erases operation. The
system can read array data on DQ7 – DQ0 on the following read cycle. However, if after the initial two read
cycles, the system determines that the toggle bit is still toggling, the system also should note whether the
value of DQ5 is high (see the section on DQ5). If it is, the system should then determine again whether the
toggle bit is toggling, since the toggle bit might have stopped toggling just as DQ5 went high. If the toggle bit
is no longer toggling, the device has successfully completed the program or erases operation. If it is still
toggling, the device did not complete the operation successfully, and the system must write the reset
command to return to reading array data. The remaining scenario is that the system initially determines that
the toggle bit is toggling and DQ5 has not gone high. The system may continue to monitor the toggle bit and
DQ5 through successive read cycles, determining the status as described in the previous paragraph.
Alternatively, it can choose to perform other system tasks. In this case, the system must start at the beginning
of the algorithm when it returns to determine the status of the operation. Refer to
Figure 7.4, Write Operation
Status Flowchart on page 38
for more details.
™
June 6, 2007 S29PL-N_00_A5
S29PL-N MirrorBit
Flash Family
39