AT88SC0204C

11

2022JS–SMEM–3/09

8.2.

Synchronous 2-wire Serial Interface

applications using CryptoMemory in standard plastic packages, this is the only communication protocol.

•

•

Figure 11.

Synchronous 2-wire Protocol

Vcc

I/O-SDA

RST

CLK-SCL

1

2

3

45

Note

:

Five clock pulses must be sent before the first command is issued.

9.

Communication Security Modes

Communications between the device and host operate in three basic modes. Standard mode is the default mode for

the device after power-up. Authentication mode is activated by a successful authentication sequence. Encryption mode

is activated by a successful encryption activation following a successful authentication.

Table 4.

Communication Security Modes

(1)

Mode

Configuration Data

User Data

Passwords

Data Integrity Check

Standard

clear

clear

clear

MDC

(1)

Authentication

clear

clear

encrypted

MAC

(1)

Encryption

clear

encrypted

encrypted

MAC

(1)

Note

:

1. Configuration data include viewable areas of the Configuration Zone except the passwords:

MDC: Modification Detection Code

MAC: Message Authentication Code.