S29AL004D SPANSION, S29AL004D Datasheet - Page 32

• Manufacturer Part Number: S29AL004D
• Description: 4 Megabit (512 Kx 8-Bit/256 K x 16-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
• Manufacturer: SPANSION

30
sector erase commands is always less than 50 µs. See also the
Command Sequence‚ on page
After the sector erase command sequence is written, the system should read the
status on DQ7 (Data# Polling) or DQ6 (Toggle Bit I) to ensure the device has ac-
cepted the command sequence, and then read DQ3. If DQ3 is 1, the internally
controlled erase cycle has begun; all further commands (other than Erase Sus-
pend) are ignored until the erase operation is complete. If DQ3 is 0, the device
(Note 1)
Notes:
1. Read toggle bit twice to determine whether or not it
2. Recheck toggle bit because it may stop toggling as
is toggling. See text.
DQ5 changes to 1. See text.
No
Figure 6. Toggle Bit Algorithm
Reset Command
Complete, Write
Read DQ7–DQ0
Read DQ7–DQ0
Read DQ7–DQ0
Program/Erase
A d v a n c e
Operation Not
Toggle Bit
Toggle Bit
= Toggle?
DQ5 = 1?
= Toggle?
22.
START
Twice
S29AL004D
Yes
Yes
Yes
(Notes
1, 2)
I n f o r m a t i o n
Operation Complete
No
No
Program/Erase
Sector Erase
S29AL004D_00_A1 February 18, 2005