SCS152

DS40150B-page 2

Preliminary

© 1997 Microchip Technology Inc.

1.0

PIN DEFINITIONS

2.0

DEVICE OPERATION

During the life of the SCS152, it goes through the fol-

lowing stages:

• Manufacture and wafer probing

• Waffle pack and transportation

• Personalization and final application.

Various fields in the memory map must be initialized.

These include the first 24 bits in the memory map, the

transport code, and the mode bits. The first 24 bits in

the memory map typically identifies the device in its

final application. The device has two principle modes:

issuer mode and user mode. In issuer mode, all access

to the device (except one field) is blocked before a cor-

rect transport code has been presented to the device.

Thus, the transport code protects the device against

theft, before it is personalized.

During

personalization,

all

fields,

except

(Chip

Identification Data (CID), are initialized for the intended

application: the device serial number is programmed,

the token counter is set to its proper value, the user

data field is initialized, and the transport code is erased

and replaced with a cryptographic key.

After power has been applied to the device, the I/O pin

the SCS152 is ready to accept commands. These com-

mands typically read the memory content serially. The

first bit at address 0 is initially driven on the I/O line.

Each read clock pulse increments the internal address

counter and reads the resulting bit from EEPROM. This

serial data stream is composed of various fields pre-

sented in Table 2-1.

2.1

CID Field

The device CID field contains a device identification

code, which is programmed during wafer probe and

cannot be changed later. These bits typically identify

the type of the device to the system in the application.

2.2

SER Field

The SER field contains the device serial number which

identifies the individual device. It is programmed while

the device is in issuer mode during the personalization

stage.

2.3

ISS Field

The ISS field indicates whether the device is in issuer

mode as determined by the CFG field. This is purely an

external view of the CFG field and exists as such for

compatibility reasons.

ISO

Pin Name

I/O Type

Description

C1

Power

Power connection

C2

SCI

INPUT

Command input to the device controller

C3

SCK

INPUT

Command execution clock input

C5

GND

Power

Power connection

C7

SDIO

Bidir (O.D.)

Open drain serial data I/O line

TABLE 2-1:

EXTERNAL

REPRESENTATION OF THE

INTERNAL MEMORY MAP

Field

Name

Address

Size

Description

CID

0…23

24

Chip identification

data

SER

24…63

40

Serial number

ISS

64

1

Issuer mode status

D4

65…71

7

Digit 4

D3

72…79

8

Digit 3

D2

80…87

8

Digit 2

D1

88…95

8

Digit 1

D0

96…103

8

Digit 0

CFG

104…107

4

Configuration data

USER0

108…147

40

User area

UKEY0

148…211

64

Key area 0 which

also acts as the

transport code in

issuer mode

212…275

64

Undefined