Table of Contents

Features.......................................................................................................................... 1

Packages.........................................................................................................................1

Package Types (not to scale).......................................................................................... 2

Description.......................................................................................................................2

System Configuration Using Single-Wire Serial EEPROMs............................................3

Block Diagram................................................................................................................. 3

1. Electrical Characteristics........................................................................................... 6

1.1.

Absolute Maximum Ratings(1)...................................................................................................... 6

1.2.

AT21CS01/11 DC and AC Operating Range................................................................................6

1.3.

AT21CS01 DC Characteristics(1)..................................................................................................6

1.4.

AT21CS11 DC Characteristics(1).................................................................................................. 7

1.5.

AT21CS01/11 AC Characteristics.................................................................................................8

2. Pin Descriptions.......................................................................................................11

2.1.

No Connect.................................................................................................................................11

2.2.

Serial Input and Output...............................................................................................................11

3. Device Operation and Communication....................................................................12

3.1.

Single-Wire Bus Transactions.................................................................................................... 12

4. Device Addressing and I2C Protocol Emulation...................................................... 18

4.1.

Memory Organization................................................................................................................. 18

5. Available Opcodes...................................................................................................20

5.1.

EEPROM Access (Opcode Ah)..................................................................................................20

5.2.

Security Register Access (Opcode Bh)...................................................................................... 20

5.3.

Lock Security Register (Opcode 2h).......................................................................................... 20

5.4.

ROM Zone Register Access (Opcode 7h)..................................................................................20

5.5.

Freeze ROM Zone State (Opcode 1h)....................................................................................... 21

5.6.

Manufacturer ID Read (Opcode Ch).......................................................................................... 21

5.7.

Standard Speed Mode (Opcode Dh)..........................................................................................21

5.8.

High-Speed Mode (Opcode Eh)................................................................................................. 21

6. Write Operations......................................................................................................22

6.1.

Device Behavior During Internal Write Cycle............................................................................. 22

6.2.

Byte Write...................................................................................................................................22

6.3.

Page Write..................................................................................................................................23

6.4.

Writing to the Security Register..................................................................................................23

6.5.

Locking the Security Register.....................................................................................................24

6.6.

Setting the Device Speed...........................................................................................................25

AT21CS01/AT21CS11

Datasheet

DS20005857A-page 4