Microcontroller Using the different chips shown design an 80

Microcontroller

Using the different chips shown, design an 8051 based system by connecting all signals given to implement a system with an external 16KB ROM and 16KB RAM (both). Moreover, explicitly give address range for each memory unit (according to your design. Assumptions: Code memory completely implemented externally (do not use on-chip ROM) Use ROM chips shown to implement ROM memory, and RAM chips to implement RAM. 74LSI88 chip: G2A (active low), G2B (active low), and G1 (active high) are enable signals for decoder and CBA are its input (i.e. A is least significant bit).

Solution

he general schematic diagram of 8051 microcontroller is shown above. We can see 3 system inputs, 3 control signals and 4 ports (for external interfacing). A Vcc power supply and ground is also shown. Now lets explain and go through each in detail. System inputs are necessary to make the micro controller functional. So the first and most important of this is power, marked as Vcc with a GND (ground potential). Without proper power supply, no electronic system would work. XTAL 1 and XTAL 2 are for the system clock inputs from crystal clock circuit. RESET input is required to initialize microcontroller to default/desired values and to make a new start.

There are 3 control signals, EA,PSEN and ALE. These signals known as External Access (EA), Program Store Enable (PSEN), and Address Latch Enable (ALE) are used for external memory interfacing