D a t a S h e e t
10.13 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 entered the Erase Suspend mode. Toggle Bit I may be read at any address, 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. The system may use either OE# or CE# to control the read cycles. 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 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 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 55).
If a program address falls within a protected sector, DQ6 toggles for approximately 1 µs after the program
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.
Table 10.5 on page 60 shows the outputs for Toggle Bit I on DQ6. Figure 10.6 on page 58 shows the toggle
bit algorithm. Figure 15.9 on page 70 shows the toggle bit timing diagrams. Figure 15.10 on page 70 shows
the differences between DQ2 and DQ6 in graphical form. See also the subsection on DQ2: Toggle Bit II
on page 58.
November 16, 2007 S29GL-N_01_09
S29GL-N MirrorBit® Flash Family
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SPANSION [ SPANSION ]
