AS29F400
Preliminary information
®
READ codes
Mode
A17–A12
A6
L
A1
L
A0
L
Code
MFR code (Alliance Semiconductor)
X
X
X
X
X
52h
×8 T boot
×8 B boot
×16 T boot
×16 B boot
L
L
H
H
H
H
23h
L
L
ABh
Device code
L
L
2223h
22ABh
L
L
01h protected
00h unprotected
Sector protection
Sector address
L
H
L
Key: L =Low (<VIL); H = High (>VIH); X =Don’t care; T = top; B = bottom
Command format
1st bus write cycle 2nd bus write cycle 3rd bus write cycle
4th bus write cycle
5th bus write cycle 6th bus write cycle
Required
bus cycles Address
Command sequence
Reset/Read
Data
F0h
Address
Data
Address
Data
Address
Data
Address Data Address
Data
Read
Address
1
4
XXXXh
Read Data
×16
Reset/Read
×8
5555h
AAAAh
2AAAh
5555h
5555h
AAAAh
Read
Data
AAh
AAh
55h
55h
F0h
Read Address
2223h
(T)
22ABh (B)
×16
5555h
AAAAh
2AAAh
5555h
5555h
AAAAh
01h
Device code
23h (T)
ABh (B)
×8
AutoselectI
4
90h
D Read
00h
52h
MFR code
×16/×8
XXX02h
01 = protected
Sector protection
00 = unprotected
×16
×8
5555h
AAAAh
5555h
AAAAh
5555h
AAAAh
XXXXh
XXXXh
2AAAh
5555h
2AAAh
5555h
2AAAh
5555h
5555h
AAAAh
5555h
AAAAh
5555h
AAAAh
Program
Address
Program
Data
Program
4
6
6
AAh
AAh
AAh
55h
55h
55h
A0h
80h
80h
×16
×8
5555h
AAAAh
5555h
AAAAh
2AAAh
5555h
AAAAh
Chip Erase
Sector Erase
AAh
AAh
55h
55h
10h
30h
5555h
2AAAh
5555h
×16
×8
Sector
Address
Sector Erase Suspend
Sector Erase Resume
1
1
B0h
30h
1
2
3
4
5
6
Bus operations defined in "Mode definitions," on page 3.
Reading from and programming to non-erasing sectors allowed in Erase Suspend mode.
Address bit A15 = X = Don’t care for all address commands except Program Address and Sector Address.
Address bit A16 = X = Don’t care for all address commands except Program Address and Sector Address.
Address bit A17 = X = Don’t care for all address commands except Program Address and Sector Address.
System should generate address patterns: ×16 mode - 5555h or 2AAAh to addresses A0–A14; ×8 mode - AAAAh or 5555h to addresses A-1–A14.
5
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
