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Checks whether sector erase timer window is open. If DQ3 = 1, erase is in progress; no
Sector erase timer (DQ3) commands will be accepted. If DQ3 = 0, the device will accept sector erase commands. Check
DQ3 before and after each sector erase command to verify that the command was accepted.
During sector erase, DQ2 toggles with OE or CE only during an attempt to read a sector being
erased. During chip erase, DQ2 toggles with OE or CE for all addresses. If DQ5 = 1, DQ2 toggles
Toggle bit 2 (DQ2)
only at sector addresses where failure occurred, and will not toggle at other sector addresses. Use
DQ2 in conjunction with DQ6 to determine whether device is in auto erase or erase suspend
mode.
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2nd bus write
cycle
3rd bus write
cycle
4th bus
read/ write cycle
5th bus
write cycle
6th bus
write cycle
1st bus write cycle
Command
sequence
Required
bus cycles
Address
Data
Address
Data
Address
Data
Address
Data
Address
Data
Address
Data
Read
Data
Reset/ Read
1
4
4
XXXXh
F0h Read Address
Read
Data
Reset/ Read
5555h
5555h
AAh
AAh
2AAAh
2AAAh
55h
55h
5555h
F0h Read Address
00h
MFR code
Autoselect ID Read
top boot
52h
B0h
34h
01h
Device code
bottom
boot
5555h
90h
XXX02h
Sector
protection
01h = protected
00h = unprotected
Program Program
Progra
m
4
6
6
5555h
5555h
5555h
AAh
AAh
AAh
2AAAh
2AAAh
2AAAh
55h
55h
55h
5555h
5555h
5555h
A0h
80h
80h
Address
Data
Chip Erase
5555h
AAh
2AAAh
2AAAh
55h
55h
5555h
10h
30h
Sector
Address
Sector Erase
5555h
AAh
Sector Erase Suspend
Sector Erase Resume
1
1
XXXXh
XXXXh
B0h
30h
1
2
3
4
5
Bus operations defined in "Mode definitions," on page 4.
Reading from or programming to non-erasing sectors allowed in Erase Suspend mode.
Address bit A15–A17 = X = Don’t care for all address commands except Program Address and Sector Address.
System should generate address patterns: 5555h or 2AAAh to address A0–A14.
A = 0, A = 1, A = 0 for sector protect verify; sector selected on A17-A13.
0
1
6
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