MEMEX

APPLICATION FILE PAGE

MEMEX.DSN

MEMEX.ASM

Proteus VSM design file created as ISIS interactive schematic

Source code file created using text editor within ISIS interactive schematic

 

OPERATION

 

The system shows how to expand the memory in an MCU system, so that it is more like a conventional microprocessor system.

 

Two conventional 32k RAM chips are connected to the MCU by an address bus (Port D) and data bus (Port C). System control lines use Port B. The low address bits are fed direct to the RAM chips, with the high bits stored in address latches. The address decoder allows up to 8 chips to be included in the system.

 

The test program writes and reads every location, and the LED indicates if the test fault has been set.