HN58V65A Datasheet, PDF (23/28 Pages) Hitachi Semiconductor – 64 k EEPROM (8-kword x 8-bit) Ready/Busy function, RES function (HN58V66A)

HN58V65A Series, HN58V66A Series
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 bytes code is input.
Address
Data
1555
AA
↓
↓
0AAA
55
↓
↓
1555
A0
↓
↓
Write address Write data } Normal data input
Software data protection mode can be cancelled 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
cancelling cycle, the data cannot be written.
Address
1555
↓
0AAA
↓
1555
↓
1555
↓
0AAA
↓
1555
Data
AA
↓
55
↓
80
↓
AA
↓
55
↓
20
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.
Rev.3.00, Dec. 04.2003, page 23 of 26