1. INTRODUCTION TO MEMORY AND MEMORY DESIGN 1
FOR B.S ( BIO MEDICAL ), IBT,LUMHS,JAMSHORO BY
ENGR. M.ZAKIR SHAIKH

2. MEMORY INTERFACE
Whether simple or complex, every microprocessor based system has a MEMORY system.
The Intel family of microprocessors are no different from any other in this respect.
Two main types of memory: RAM & ROM.
ROM contains System Software & Permanent System Data.
RAM contains Temporary data & Applications Software.

4. RAM
STANDS FOR :
RANDOM ACCESS MEMORY
DEFINITION:
Random Access Memory or RAM is a form of data storage that can be accessed randomly at any time, in any order and from any physical location., allowing quick access and manipulation.

6. ROM STANDS FOR : READ ONLY MEMORY DEFINITION :
Read-only memory or ROM is also a form of data storage that can not be easily altered or reprogrammed.

7. USE :
ROM stores the program required to initially boot the computer. It only allows reading.
VOLATILITY :
It is non-volatile i.e. its contents are retained even when the device is powered off.
TYPES:
The types of ROM include PROM, EPROM and EEPROM…..

8. ROM chips are commonly used in gaming system cartridges, like the original Nintendo, Game boy, Sega Genesis, and a number of others. The game cartridge stores the game programming on a ROM chip which is read by the game console when the cartridge is inserted into the console.

9. ROM chips can also be found in computers, to store the programming needed to begin the initial boot up process when turning on a computer. Using non-volatile storage is the only way to begin the start up process for computers and other devices that use similar a start up process. The most common type of programmable ROM (PROM) chip in a computer is the BIOS.

10. CACHE MEMORY
Cache memory is a special high speed memory that the CPU can access quickly.
It is used in computers with very fast CPUs, so that these CPUs don’t have to wait for Data to be delivered from RAM.
The most frequent used instructions are kept in the Cache memory.
This allows the CPU to run faster because it does not have to take time to swap instructions in and out of RAM.

11. MEMORY PIN CONNECTIONS
Every memory device must have:
Address inputs
Data inputs & outputs
Some type of selection input
At least one control input to select Read/Write operation.

12. ADDRESS CONNECTIONS: All memory devices have address inputs that select a memory location within the memory device.

13. Most common memory devices have locations of:1K 8K
16K
32K
64K
128K
256K
521K
1024K (1MB)
4MB
8MB
16MB
32MB
64MB
128MB
256MB
512MB
1GB

14. A 1K memory device has 10 address pins (A0 – A9)
A 1K memory device has 10 address pins (A0 – A9). 4K memory device has 12 address connections, an 8K device has 13, & so forth.
A device that contains 1M locations requires a 20-bit Addresses (A0 – A19).
A device that contains 16M location requires a 24-bit addresses (A0 – A23).
A device that contains 4G location requires 32-bit address.

15. Fig. The pin-out of 30-pin SIMM
organized as 4M x 9.

16. Fig. The pin-out of 72-pin SIMM organized as 4M x 36.