System for programming EEPROM with data loaded in ROM by sending switch signal to isolate EEPROM from host system

摘要

An EEPROM programming circuit is disclosed which provides for the on-board programming of a EEPROM memory using: a microprocessor, a bootstrap ROM, a UART communications port, and a Eccles-Jordan flip flop switch system. These elements are electrically connected to a host system and the EEPROM by a central data bus. In normal operation, the host system sends a first set of data signals through the circuit to the EEPROM, which produces a set of processed signals. In operation in the programming mode the host system sends a second set of data signals to cause the microprocessor to send a switch signal to the Eccles-Jordan flip flop switch and to the bootstrap ROM. The bootstrap ROM contains the program code that forms the programs that are used to program the EEPROM. The Eccles-Jordan flip flop switch works with the communications port to serve as a means of isolating the EEPROM from the host system and directly connecting to EEPROM is the bootstrap ROM for programming when receiving the switch signal from the microprocessor.