| 摘要 |
<p>PURPOSE:To check the margin of an EEPROM with a simple tester by providing a margin check program means incorporated in a ROM and a D/A converter, which is connected to a EEPROM gate, on a chip. CONSTITUTION:A ROM 2 where an EEPROM margin check program 8 is incorporated and a D/A converter 7 connected to the gate of an EEPROM 3 are constituted on the chip adjacently to a RAM 1. Then, an analog voltage applied to the gate of the EEPROM 3 is generated in a chip. Write and read operations of the EEPROM are automatically performed by the program 8 in the ROM 2 without external signals. Consequently, the burden on a tester is considerably reduced by this single chip microcomputer, and the margin of the EEPROM is checked with the simple tester.</p> |
