HN58V256AT-12 HITACHI [Hitachi Semiconductor], HN58V256AT-12 Datasheet - Page 20

• Manufacturer Part Number: HN58V256AT-12
• Description: 256k EEPROM (32-kword x 8-bit) Ready/Busy and RES function (HN58V257A)
• Manufacturer: HITACHI [Hitachi Semiconductor]

HN58V256A Series, HN58V257A Series
3. Software data protection
To prevent unintentional programming, this device has the software data protection (SDP) mode. The SDP is
enabled by inputting the following 3 bytes code and write data. SDP is not enabled if only the 3 bytes code is
input. To program data in the SDP enable mode, 3 bytes code must be input before write data.
The SDP mode is disabled by inputting the following 6 bytes code. Note that, if data is input in the SDP
disable cycle, data can not be written.
The software data protection is not enabled at the shipment.
Note: There are some differences between Hitachi’s and other company’s for enable/disable sequence of
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software data protection. If there are any questions , please contact with Hitachi sales offices.
Write address
Address
2AAA
5555
5555
Address
2AAA
2AAA
5555
5555
5555
5555
Write data }
Data
AA
A0
55
Normal data input
Data
AA
AA
55
80
55
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