X76F200

2

PIN DESCRIPTIONS

Serial Clock (SCL)

The SCL input is used to clock all data into and out of the

device.

Serial Data (SDA)

SDA is an open drain serial data input/output pin. During a

read cycle, data is shifted out on this pin. During a write

cycle, data is shifted in on this pin. In all other cases, this pin is

in a high impedance state.

Reset (RST)

RST is a device reset pin. When RST is pulsed high the

X76F200 will output 32 bits of fixed data which conforms

to the standard for “synchronous response to reset”.

The part must not be in a write cycle for the response to reset

to occur. See Figure 7. If there is power interrupted

during the Response to Reset, the response to reset will be

aborted and the part will return to the standby state.

The response to reset is "mask programmable" only!

DEVICE OPERATION

The X76F200 memory array consists of thirty 8-byte

sectors. Read or write access to the array always begins

at the first address of the sector. Read operations then can

continue indefinitely. Write operations must total 8

bytes.

There are two primary modes of operation for the

X76F200; Protected READ and protected WRITE.

Protected operations must be performed with one of two

8-byte passwords.

The basic method of communication for the device is

generating a start condition, then transmitting a

command, followed by the correct password. All parts will be

shipped from the factory with all passwords equal to

‘0’. The user must perform ACK Polling to determine the validity

of the password, before starting a data transfer

(see Acknowledge Polling.) Only after the correct password

is accepted and a ACK polling has been

performed, can the data transfer occur.

To ensure the correct communication, RST must remain LOW

under all conditions except when running a

“Response to Reset sequence”.

Data is transferred in 8-bit segments, with each transfer being

followed by an ACK, generated by the receiving

device.

If the X76F200 is in a nonvolatile write cycle a “no A

CK” (SDA=High) response will be issued in response to

loading of the command byte. If a stop is issued prior to

the nonvolatile write cycle the write operation will be

terminated and the part will reset and enter into a

standby mode.

The basic sequence is illustrated in Figure 1.

PIN NAMES

PIN CONFIGURATION

After each transaction is completed, the X76F200 will reset

and enter into a standby mode. This will also be the

response if an unsuccessful attempt is made to access a

protected array.

Symbol

Description

SDA

Serial Data Input/Output

SCL

Serial Clock Input

RST

Reset Input

Vcc

Supply Voltage

Vss

Ground

NC

No Connect

SDA

RST

SCL

NC

1

2

3

4

7

8

6

5

SOIC

RST

SCL

NC

SDA

Smart Card Module

NC

NC

NC

GND

NC

RST

SCL

SDA

Vss

1

2

3

4

7

8

6

5

PDIP

NC

NC

NC

RST

SDA

NC

NC

1

2

3

4

7

8

6

5

SCL

NC

TSSOP