w49v002a Winbond Electronics Corp America, w49v002a Datasheet - Page 11

• Manufacturer Part Number: w49v002a
• Description: 256k X 8 Cmos Flash Memory With Lpc Interface
• Manufacturer: Winbond Electronics Corp America

Command Codes for Product Identification and Boot Block Lockout Detection
Software Product Identification and Boot Block Lockout Detection Acquisition Flow
Notes for software product identification/boot block lockout detection:
(1) Data Format: DQ7 DQ0 (Hex); Address Format: A14 A0 (Hex)
(2) A1 A17 = V
(3) The device does not remain in identification and boot block lockout detection mode if power down.
(4) If the DQ0 of output data is "1," the boot block programming lockout feature is activated; if the DQ0 of output data "0," the lockout feature
is inactivated and the block can be programmed.
(5) The device returns to standard operation mode.
(6) Optional 1-write cycle (write F0 hex at XXXX address) can be used to exit the product identification/boot block lockout detection.
SEQUENCE
1 Write
2 Write
3 Write
BYTE
IL
; manufacture code is read for A0 = V
Product
Identification
Entry (1)
address 5555
address 5555
address 2AAA
Pause 10 S
Load data AA
Load data 55
Load data 90
SOFTWARE PRODUCT IDENTIFICATION /
BOOT BLOCK LOCKOUT DETECTION
to
to
to
ADDRESS
5555
2AAA
5555
Pause 10 S
Mode (3)
Identification
and Boot Block
Lockout Detection
Product
ENTRY
DQ0 of data outputs = 1/0
Read address = 00002
Read address = 00000
Read address = 00001
IL
; device code is read for A0 = V
data = DA
data = B0
DATA
AA
55
90
- 11 -
(4)
(2)
(2)
Preliminary W49V002A
SOFTWARE PRODUCT IDENTIFICATION /
IH
BOOT BLOCK LOCKOUT DETECTION
.
ADDRESS
Identification Exit(6)
Product
5555H
2AAAH
5555H
Publication Release Date: April 2001
Normal Mode
address 5555
Load data 55
address 2AAA
Load data AA
address 5555
Load data F0
Pause 10 S
Pause 10 S
EXIT (6)
to
to
to
DATA
AAH
55H
F0H
(5)
Revision A1