at34c02b ATMEL Corporation, at34c02b Datasheet - Page 11

• Manufacturer Part Number: at34c02b
• Description: Two-wire Serial Eeprom With Permanent And Reversible Software Write Protect 2k 256 X 8
• Manufacturer: ATMEL Corporation

Table 8.
3417E–SEEPR–1/07
WP Connected to GND or Floating
Read RSWP
Read RSWP
Clear RSWP
Clear RSWP
Read PSWP
Read PSWP
Command
Set RSWP
Set RSWP
Set PSWP
Set PSWP
1010
1010
1010
1010
WP Connected to GND or Floating
R/W Bit
W
W
W
W
W
W
W
W
W
R
R
R
R
R
Permanent Write
Protect Register
Not Programmed
Not Programmed
Not Programmed
Not Programmed
Programmed
Programmed
Programmed
Programmed
PSWP
X
X
X
X
X
X
Table 6. Write Protection
Table 7. VHV
Note:
Command
Set PSWP
Set RSWP
Clear RSWP
VHV
VHV - VCC > 4.8V
Reversible Write
Protect Register
Not Programmed
Not Programmed
Not Programmed
Programmed
Programmed
Programmed
RSWP
X
X
X
X
X
X
X
X
A2
A2
0
0
A1
A1
Pin
0
1
Acknowledgment
from Device
VHV
VHV
A0
A0
Min
No ACK
No ACK
No ACK
No ACK
No ACK
7
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
B7
0
0
0
B6
Action from Device
Can write to second Half (80H - FFH) only
Can write to second Half (80H - FFH) only
Can write to full array
STOP - Indicates permanent write protect register is
programmed
Read out data don't care. Indicates PSWP register
is not programmed
STOP - Indicates permanent write protect register is
programmed
Program permanent write protect register
(irreversible)
STOP - Indicates reversible write protect register is
programmed
Read out data don't care. Indicates RSWP register
is not programmed
STOP - Indicates reversible write protect register is
programmed
Program reversible write protect register (reversible)
STOP - Indicates permanent write protect register is
programmed
Clear (unprogram) reversible write protect register
(reversible)
1
1
1
B5
1
1
1
Max
10
Preamble
B4
0
0
0
B3
A2
0
0
B2
A1
0
1
Units
V
B1
A0
1
1
RW
B0
0
0
0
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