HN58V65AI/HN58V66AI/HN58V65A-SR/HN58V66A-SR Series

Rev.3.00, Feb.02.2004, page 23 of 26

3. Software data protection

To prevent unintentional programming caused by noise generated by external circuits, this device has

the software data protection function. In software data protection mode, 3 bytes of data must be input

before write data as follows. And these bytes can switch the non-protection mode to the protection

mode. SDP is enabled if only the 3 byte code is input.

Data

AA

↓

55

↓

A0

↓

Write data }

Address

1555

↓

0AAA

↓

1555

↓

Write address

Normal data input

Software data protection mode can be canceled by inputting the following 6 bytes. After that, this device

turns to the non-protection mode and can write data normally. But when the data is input in the canceling

cycle, the data cannot be written.

Data

AA

↓

55

↓

80

↓

AA

↓

55

↓

20

Address

1555

↓

0AAA

↓

1555

↓

1555

↓

0AAA

↓

1555

The software data protection is not enabled at the shipment.

Note:

There are some differences between Renesas Technology’s and other company’s for enable/disable

sequence of software data protection. If there are any questions, please contact with Renesas

Technology’s sales offices.