AT34C02B View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

AT34C02B

Two-wire Serial EEPROM with Permanent and Reversible Software Write Protect

Atmel Corporation 

AT34C02B

Table 6. Write Protection

Pin

Preamble

RW

Command

A2 A1 A0 B7 B6 B5 B4 B3 B2 B1 B0

Set PSWP

A2 A1 A0

0

1

1

0 A2 A1 A0 0

Set RSWP

0

0 VHV 0

1

1

0

0

0

1

0

Clear RSWP 0

1 VHV 0

1

1

0

0

1

1

0

Table 7. VHV

Min

VHV

7

Note: VHV - VCC > 4.8V

Max

Units

10

V

Table 8. WP Connected to GND or Floating

WP Connected to GND or Floating

Command

R/W Bit

Permanent Write

Protect Register

PSWP

1010

R

X

1010

W

Programmed

1010

W

X

1010

W

Not Programmed

Reversible Write

Protect Register

RSWP

X

X

Programmed

Not Programmed

Acknowledgment

from Device

ACK

ACK

ACK

ACK

Action from Device

Can write to second Half (80H - FFH) only

Can write to second Half (80H - FFH) only

Can write to full array

Read PSWP

R

Programmed

X

Read PSWP

R

Not Programmed

X

Set PSWP

W

Programmed

X

Set PSWP

W

Not Programmed

X

No ACK

ACK

No ACK

ACK

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)

Read RSWP

Read RSWP

Set RSWP

Set RSWP

Clear RSWP

Clear RSWP

R

X

Programmed

R

X

Not Programmed

W

X

Programmed

W

X

Not Programmed

W

Programmed

X

W

Not Programmed

X

No ACK

ACK

No ACK

ACK

No ACK

ACK

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)

11

3417E–SEEPR–1/07

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