单片微机的P1.0(SCL)和P1.1(SDA)两根I/O口线构成虚拟I2C总线，扩展串行EEPROM芯片24C02。对扩展的串行数据存储器24C02进行自检，若每一单元读/写都正确，则把片内RAM中20H单元内容清0，否则置20H内容为FFH。-80C51 single-chip microcomputer using P1.0 (SCL) and P1.1 (SDA) two I/O port lines constitute a virtual I2C bus, extended serial EEPROM chip 24C02. The extended self-test 24C02 serial data memory, if each unit read/write is correct, put the unit 20H-chip RAM contents to 0, or set the contents of 20H to FFH.