s29jl064h Meet Spansion Inc., s29jl064h Datasheet - Page 40

• Manufacturer Part Number: s29jl064h
• Description: 64 Megabits 8 M X 8-bits / 4 M X 16-bits
• Manufacturer: Meet Spansion Inc.

11.4
40
DQ2: Toggle Bit II
Note
The system should recheck the toggle bit even if DQ5 = 1 because the toggle bit may stop toggling as DQ5 changes to 1. See the
subsections on DQ6 and DQ2 for more information.
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.
(The system may use either OE# or CE# to control the read cycles.) 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
outputs for DQ2 and DQ6.
Figure 11.2 on page 40
explains the algorithm. See also
timing diagram.
Figure 17.11 on page 53
shows the toggle bit algorithm in flowchart form, and
DQ6: Toggle Bit I on page
No
Figure 11.2 Toggle Bit Algorithm
S29JL064H
shows the differences between DQ2 and DQ6 in graphical form.
Complete, Write
Read Byte Twice
Reset Command
Program/Erase
Operation Not
Address =VA
Address =VA
Address = VA
(DQ7–DQ0)
(DQ7–DQ0)
(DQ7–DQ0)
Read Byte
Read Byte
Toggle Bit
DQ5 = 1?
Toggle Bit
D a t a
= Toggle?
= Toggle?
START
Yes
Yes
Yes
S h e e t
Operation Complete
39.
No
No
Program/Erase
Figure 17.10 on page 52
Table 11.1 on page 42
S29JL064H_00_A7 September 19, 2007
DQ2: Toggle Bit II on page 40
shows the toggle bit
to compare