W29C020-90 Winbond Electronics, W29C020-90 Datasheet - Page 6

• Manufacturer Part Number: W29C020-90
• Manufacturer: Winbond Electronics

Specifications of W29C020-90

• Density: 2Mb
• Access Time (max): 90ns
• Interface Type: Parallel
• Boot Type: Bottom/Top
• Address Bus: 18b
• Operating Supply Voltage (typ): 5V
• Operating Temp Range: 0C to 70C
• Package Type: PDIP
• Program/erase Volt (typ): 5V
• Sync/async: Asynchronous
• Operating Temperature Classification: Commercial
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Word Size: 8b
• Number Of Words: 256K
• Supply Current: 50mA
• Mounting: Through Hole
• Pin Count: 32
• Lead Free Status / Rohs Status: Supplier Unconfirmed

Command Codes for Software Data Protection
Software Data Protection Acquisition Flow
Notes for software program code:
Data Format: DQ7 DQ0 (Hex)
Address Format: A14 A0 (Hex)
BYTE SEQUENCE
0 Write
1 Write
2 Write
3 Write
4 Write
5 Write
(Optional page-load
operation)
TO ENABLE PROTECTION
ADDRESS
2AAAH
5555H
5555H
Software Data Protection
Enable Flow
-
-
-
Sequentially load
up to 128 bytes
Load data AA
address 5555
address 2AAA
of page data
Load data 55
Load data A0
address 5555
Pause 10 mS
Exit
to
to
to
- 6 -
DATA
AAH
A0H
55H
-
-
-
Software Data Protection
Disable Flow
address 2AAA
Load data AA
address 5555
address 2AAA
address 5555
address 5555
Load data 20
Load data AA
address 5555
Load data 55
Load data 55
Load data 80
Pause 10 mS
TO DISABLE PROTECTION
ADDRESS
Exit
to
to
to
to
to
to
2AAAH
2AAAH
5555H
5555H
5555H
5555H
W29C020
DATA
AAH
AAH
55H
80H
55H
20H