$6 )
®
3UHOLPLQDU\LQIRUPDWLRQ
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
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.
Toggle bit 2 (DQ2)
&RPPDQGIRUPDW
Command
sequence
Reset/Read
Reset/Read
Required
bus cycles
1
4
1st bus write cycle
Address
XXXXh
5555h
Data
F0h
AAh
2nd bus write
cycle
Address
Read Address
2AAAh
Data
Read
Data
55h
3rd bus write
cycle
Address
Data
4th bus
read/write cycle
Address
Data
5th bus
write cycle
Address
Data
6th bus
write cycle
Address
Data
5555h
F0h
Read Address
00h
MFR code
01h
Device code
XXX02h
Sector
protection
Read
Data
52h
B0h
Autoselect ID Read
top boot
bottom
boot
4
5555h
AAh
2AAAh
55h
5555h
90h
34h
01h = protected
00h = unprotected
Program
Data
AAh
AAh
2AAAh
2AAAh
55h
55h
5555h
Sector
Address
10h
30h
Progra
m
Chip Erase
Sector Erase
4
6
6
1
1
5555h
5555h
5555h
XXXXh
XXXXh
AAh
AAh
AAh
B0h
30h
2AAAh
2AAAh
2AAAh
55h
55h
55h
5555h
5555h
5555h
A0h
80h
80h
Program
Address
5555h
5555h
)/$6+
Sector Erase Suspend
Sector Erase Resume
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
= 0, A
1
= 1, A
6
= 0 for sector protect verify; sector selected on A17-A13.
$//,$1&(6(0,&21'8&725
',' $
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
