5

AT88SC153

1016D–SMEM–04/04

Fuses

FAB, CMA, and PER are nonvolatile fuses blown at the end of each card life step. Once

blown, these EEPROM fuses can not be reset.

•

The FAB fuse is blown by Atmel prior to shipping wafers to the card manufacturer.

•

The CMA fuse is blown by the card manufacturer prior to shipping cards to the

issuer.

•

The PER fuse is blown by the issuer prior to shipping cards to the end user.

The device responds to a read fuse command with fuse byte.

Table 4. Fuse Byte

When the fuses are all “1”s, read and write are allowed in the entire memory. Before

blowing the FAB fuse, Atmel writes the entire memory to “1” and programs the fabrica-

tion subzone (except CMC and AR) and the secure code.

Note:

CMC: Card Manufacturer Code

AR: Access Rights as defined by the access registers

PW: Password

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

0000

0

PER

CMA

FAB

Table 5. Access Rights

Zone

Access

FAB = 0

CMA = 0

PER = 0

Fabrication

(Except CMC, MTZ and AR)

Read

Free

Free

Free

Write

Forbidden

Forbidden

Forbidden

Card Manufacturer

Code

Read

Free

Free

Free

Write

Secure Code

Forbidden

Forbidden

Access Registers

Read

Free

Free

Free

Write

Secure Code

Secure Code

Forbidden

Memory Test Zone

Read

Free

Free

Free

Write

Free

Free

Free

Identification

Read

Free

Free

Free

Write

Secure Code

Secure Code

Forbidden

Secret

Read

Secure Code

Secure Code

Forbidden

Write

Secure Code

Secure Code

Forbidden

Passwords

Read

Secure Code

Secure Code

Write PW

Write

Secure Code

Secure Code

Write PW

PAC

Read

Free

Free

Free

Write

Secure Code

Secure Code

Write PW

User Zones

Read

AR

AR

AR

Write

AR

AR

AR