12.7 Precautions on Program EEPROM
12.7.1 Programming Time for Program EEPROM
The program EEPROM programming time is not fixed. The time required to program different data is
different, ranging from 100us to 5ms(10ms). The CPU stops working during the programming period, and the
program needs to be well dealt with accordingly.
12.7.2 Write Verification
According to specific applications, good programming habits generally require verification of the value
written into the program EEPROM against the expected value.
12.7.3 Protection to Avoid Writing Wrongly
In some cases, the user may not want to write data to the program EEPROM. In order to prevent
accidental writing of EEPROM, various protection mechanisms are embedded in the chip. The WREN bit is
cleared when the power is turned on. Moreover, the power-on delay timer (the delay time is 18ms) Will prevent
writing to the EEPROM.
The start sequence of the write operation and the WREN bit will work together to prevent false write
operations in the following situations:
⚫ Under voltage
⚫ Power glitch
⚫ Software failure
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