R1EX25002ASA00A_15 Datasheet, PDF (20/24 Pages) Renesas Technology Corp – Serial Peripheral Interface 2k EEPROM (256-word × 8-bit) 4k EEPROM (512-word × 8-bit) Electrically Erasable and Programmable Read Only Memory

R1EX25002Axx00A/R1EX25004Axx00A
Notes
Data Protection at V_CC On/Off
When V_CC is turned on or off, noise on S inputs generated by external circuits (CPU, etc) may act as a trigger and turn
the EEPROM to unintentional program mode. To prevent this unintentional programming, this EEPROM have a power
on reset function. Be careful of the notices described below in order for the power on reset function to operate
correctly.
• S should be fixed to V_CC during V_CC on/off. Low to high or high to low transition during V_CC on/off may
cause the trigger for the unintentional programming.
• V_CC should be turned on/off after the EEPROM is placed in a standby state.
• V_CC should be turned on from the ground level (V_SS) in order for the EEPROM not to enter the unintentional
programming mode.
• V_CC turn on speed should be slower than 10 µs/V.
• When WRSR or WRITE instruction is executed before V_CC turns off, V_CC should be turned off after waiting
write cycle time (t_W).
REJ03C0357-0002 Rev. 0.02 Jan.14 .2009
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