W29C020 Datasheet, PDF (8/21 Pages) Winbond – 256K X 8 CMOS FLASH MEMORY

W29C020
Command Codes for Product Identification and Boot Block Lockout Detection
BYTE
SEQUENCE
0 Write
1 Write
2 Write
3 Write
4 Write
5 Write
ALTERNATE PRODUCT (7)
IDENTIFICATION/BOOT BLOCK
LOCKOUT DETECTION ENTRY
ADDRESS
DATA
5555
AA
2AAA
55
5555
90
-
-
-
-
-
-
Pause 10 µS
SOFTWARE PRODUCT
IDENTIFICATION/BOOT BLOCK
LOCKOUT DETECTION ENTRY
ADDRESS
DATA
5555H
AAH
2AAAH
55H
5555H
80H
5555H
AAH
2AAAH
55H
5555H
60H
Pause 10 µS
SOFTWARE PRODUCT
IDENTIFICATION/BOOT BLOCK
LOCKOUT DETECTION EXIT
ADDRESS
DATA
5555H
AAH
2AAAH
55H
5555H
F0H
-
-
-
-
-
-
Pause 10 µS
Software Product Identification and Boot Block Lockout Detection Acquisition Flow
Product
Identification
Entry (1)
Load data AA
to
address 5555
Product
Identification
and Boot Block
Lockout Detection
Mode (3)
Product
Identification
Exit (1)
Load data 55
to
address 2AAA
(2)
Read address = 00000
data = DA
Load data AA
to
address 5555
Load data 80
to
address 5555
(2)
Read address = 00001
data = 45
Load data 55
to
address 2AAA
Load data AA
to
address 5555
(4)
Read address = 00002
data = FF/FE
Load data F0
to
address 5555
Load data 55
to
address 2AAA
(5)
Read address = 3FFF2
data = FF/FE
Pause 10 µS
Load data 60
to
address 5555
(6)
Normal Mode
Pause 10 µS
Notes for software product identification/boot block lockout detection:
(1) Data Format: DQ7−DQ0 (Hex); Address Format: A14−A0 (Hex)
(2) A1−A16 = VIL; manufacture code is read for A0 = VIL; device code is read for A0 = VIH.
(3) The device does not remain in identification and boot block (address 0002 Hex/3FFF2 Hex respond to first 8K/last 8K) lockout detection mode if
power down.
(4), (5) If the output data is "FF Hex," the boot block programming lockout feature is activated; if the output data "FE Hex," the lockout feature is
inactivated and the block can be programmed.
(6) The device returns to standard operation mode.
(7) This product supports both the JEDEC standard 3 byte command code sequence and original 6 byte command code sequence. For new
designs, Winbond recommends that the 3 byte command code sequence be used.
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