The document discusses microcomputers, detailing their components such as the CPU, RAM, and ROM, and their functions within a computing system. It explains RAM's role in storing changing information necessary for program execution and introduces two types of RAM: SRAM and DRAM. Additionally, VHDL source code for RAM implementation is provided, illustrating its read and write functionality.

1. KIIT COLLEGE OF ENGINEERING
Submitted by: Gaurav Bisht, Prateek Gaur & Pradeep Sheet
Group 1
B.Tech (CSE) 6th Sem

2. Name of The Topic:

3. Contents:
 Microcomputer
 Block Diagram of microcomputer
 Components of microcomputer
 RAM
 Types of RAM
 VHDL Code for RAM

4. Microcomputer:
 A microprocessor embedded in a computer is called microcomputer often with the use of SoC
(System on a Chip).
 The microprocessor is also known as the CPU of the microcomputer.
 Microcomputers are generally meant to run full-fledged Operating Systems, so they often rely on
external RAM and ROM and use common I/O peripherals and ports such as USB or RJ45
(Ethernet).

5. Block Diagram of Microcomputer:

6. Components of Microcomputer:
 CPU
- Contains Control Unit and Arithmetic Logic Unit.
- Organizes correct sequence of the processes.
- Performs all the mathematical and logical operations of the system.
 RAM
- Stores the instructions and data needed during processing and execution of programs or
commands.
 ROM
- It serves as permanent storage of data used by microprocessor.
 Interface Circuitry
- An interface between the input devices and the CPU.
 Peripheral Devices
- These are the devices which add functionality.

7. RAM:
 A microcomputer contains several types of primary memory.
 RAM (Random Access Memory) is used for storing information that changes.
 This memory in a computer is accessible to the user.
 RAM is used to store user programs that control what the CPU does.
 It stores the data used by these programs and the results of operations performed by these
programs.

8. Types of RAM:
 Integrated RAM chips are available in two forms:
1. SRAM (Static RAM):
The SRAM memories consist of circuits capable of retaining the stored information as long as the power is applied.
2. DRAM (Dynamic RAM):
DRAM stores the binary information in the form of electric charges that applied to capacitors.

9. Source Code:
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY RAM IS //Entity starts
PORT (DATAIN: IN STD_LOGIC_VECTOR (7 DOWNTO 0) ;
ADDRESS: IN STD_LOGIC_VECTOR (7 DOWNTO 0);
W_R: IN STD_LOGIC; //selection for read or write
DATAOUT: OUT STD_LOGIC_VECTOR (7 DOWNTO 0));
END ENTITY; //Entity Ends

10. Source Code (Cont.)
ARCHITECTURE BEV OF RAM IS
TYPE MEM IS ARRAY (255 DOWNTO 0) OF STD_LOGIC_VECTOR (7 DOWNTO 0); //Array declared 256X8
SIGNAL MEMORY: MEM; //To use array
SIGNAL ADDR: INTEGER RANGE 0 TO 255;
BEGIN
PROCESS (ADDRESS, DATAIN, W_R)
BEGIN
ADDR<=CONV_INTEGER (ADDRESS); //Convert to integer
IF (W_R='0') THEN //Write condition
MEMORY (ADDR) <=DATAIN;
ELSIF (W_R='1') THEN //Read condition
DATAOUT <= MEMORY (ADDR);
ELSE
DATAOUT<="ZZZZZZZZ"; //Other Condition
END IF; //End of If statement
END PROCESS; //End of Process Statement
END BEV; //End of Architecture