w39l020 Winbond Electronics Corp America, w39l020 Datasheet - Page 14

• Manufacturer Part Number: w39l020
• Description: 256k U 8 Cmos Flash Memory
• Manufacturer: Winbond Electronics Corp America

Software Product Identification and Boot Block Lockout Detection Flow Chart
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 output data in DQ0 or DQ1= " 1 " the boot block programming lockout feature is activated; if the output data
(5) The device returns to standard operation mode.
(6) Optional 1-byte cycle (write F0 hex at XXXX address) can be used to exit the product identification/boot block lockout
detection.
in DQ0 or DQ1= " 0," the lockout feature is inactivated and the matched boot block can be programmed.
Entry (1)
Identification
Product
address 5555
Pause 10
address 5555
address 2AAA
Load data AA
Load data 55
Load data 90
IL
to
to
to
; manufacture code is read for A0 = V
P
S
Mode (3)
Identification
and Boot Block
Lockout
D t ti
Product
Read address=02/3FFF2
data:in DQ0="1" or "0"
Read address = 0001
for Bottom/Top
Read address = 0000
for 64K Boot Block
for 16K Boot Block
or DQ1="1" or "0"
data = DA
data = B5
IL
; device code is read for A0 = V
- 14 -
(4)
(2)
(2)
Product
Identification Exit(6)
IH
.
Normal Mode
address 5555
Load data
55
address 2AAA
Load data AA
address 5555
Load data F0
Pause 10
to
to
to
P
W39L020
S
(5)