11

AT88SC1608

0971G–SMEM–04/04

The read fuses operation is always allowed. The device only transmits one data byte

and waits for a new command.

Write Fuses

Figure 8. Write Fuses

The write fuses operation is only allowed under secure code control and no data byte is

transmitted by the host. The fuses are blown sequentially: CMA is blown if FAB is equal

to “0”, and PER is blown if CMA is equal to “0”. If the fuses are all “0”s, the operation is

canceled and the device waits for a new command.

Once a stop condition is issued to indicate the end of the host’s write operation, the

device initiates the internal nonvolatile write cycle. An ACK polling sequence can be ini-

tiated immediately. Once blown, these fuses cannot be reset.

A

C

K

A

C

K

S

T

A

R

T

Command

Fuses Add

1 0 1 1 0 1 0 0

1 0 0 0 0 0 0 0

S

T

O

P