AT28C256-25PC Atmel, AT28C256-25PC Datasheet - Page 10

• Manufacturer Part Number: AT28C256-25PC
• Manufacturer: Atmel

Specifications of AT28C256-25PC

• Density: 256Kb
• Interface Type: Parallel
• Organization: 32Kx8
• Access Time (max): 250ns
• Write Protection: Yes
• Data Retention: 10Year
• Operating Supply Voltage (typ): 5V
• Package Type: PDIP
• Operating Temp Range: 0C to 70C
• Supply Current: 50mA
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 28
• Lead Free Status / Rohs Status: Not Compliant

21. Software Protected Write Cycle Waveforms
Notes:
19. Software Data Protection
Notes:
10
Enable Algorithm
1. A6 through A14 must specify the same page address during each high to low transition of WE (or CE) after the software
2. OE must be high only when WE and CE are both low.
1. Data Format: I/O7 - I/O0 (Hex);
2. Write Protect state will be activated at end of write
3. Write Protect state will be deactivated at end of write
4. 1 to 64 bytes of data are loaded.
AT28C256
code has been entered.
Address Format: A14 - A0 (Hex).
even if no other data is loaded.
period even if no other data is loaded.
LOAD LAST BYTE
ANY ADDRESS
ADDRESS 2AAA
LAST ADDRESS
LOAD DATA AA
ADDRESS 5555
ADDRESS 5555
LOAD DATA XX
LOAD DATA A0
LOAD DATA 55
TO
TO
TO
TO
TO
(4)
WRITES ENABLED
ENTER DATA
PROTECT STATE
(1)
(2)
20. Software Data Protection
Disable Algorithm
(1)(2)
LOAD LAST BYTE
ANY ADDRESS
ADDRESS 2AAA
ADDRESS 2AAA
LAST ADDRESS
ADDRESS 5555
ADDRESS 5555
ADDRESS 5555
ADDRESS 5555
LOAD DATA AA
LOAD DATA AA
LOAD DATA XX
LOAD DATA 55
LOAD DATA 80
LOAD DATA 55
LOAD DATA 20
TO
TO
TO
TO
TO
TO
TO
TO
(4)
EXIT DATA
PROTECT STATE
(1)
0006K–PEEPR–01/08
(3)