Guide RAM and ROM Based Digital Design

The memory is a basic component of the computer, without which any operation becomes impossible. The memory is in the form of electronic components having the capacity to retain information (the information being of binary type, 0 or 1).

Each 'bit' memory is composed of a transistor (which reads or writes a value) coupled to a capacitor (which holds the binary state: 1 when it is loaded and 0 when it is discharged). The memory is organized in rows and columns. At each intersection there is a bit of memory.

• Representation of memory
• Role of memory
• Technical specifications
• Memory Space
• Types of memory cards
• Technology
• Types of Memory
• Using Read-Only Memory

Table of contents

• Digital System Design
• Building Block Circuits
• Static Random Access Memory (SRAM)
• SRAM Blocks in PLDs
• Multiplexers, Decoders, and Programmable
• Logic Devices
• Read Only Memories
• RAM
• Random Access Memory
• Same access time to all memory locations
• Serial access memory
• About the same time for read and write
• SRAM
• Static Random Access Memory
• Built with cross coupled inverters and pass transistors
• CMOS implementation with pass transistors
• Sense amp at bottom of column
• RAM Blocks and Register Files
• DRAM
• Uses capacitance on MOSFET gate
• Must be “refreshed” periodically
• Restore charge on gate capacitance
• Accomplished by reading or writing to memory location
• Combinational Design with Memories