The document discusses memory interfacing with the microcontroller 8051, covering semiconductor memory fundamentals, types, structures, and decoding methods. It elaborates on various types of memories like RAM, ROM, EEPROM, and their applications in computer systems, along with practical examples and interfacing techniques. Furthermore, it includes specific examples of interfacing the 8051 microcontroller with different memory configurations.

1. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Memory Interfacing with Microcontroller 8051
Dr. Nilesh Bhaskarrao Bahadure
July 25, 2021

2. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Introduction to Memory Interfacing
1 Semiconductor Memory Fundamentals
2 Memory Types
3 Memory Structure and its requirements
4 Memory Decoding
5 Examples on Memory Interfacing

3. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Memory is simply a device that can be used to store the
information (data). The semiconductor memories are
extensively used because of their small size, low cost, high
speed, high reliability and ease of expansion of the memory
size, it consists mainly a flip flops one flip flop can hold one bit
of data and some additional circuitry such as buffers

4. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Semiconductor Memory I

5. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Semiconductor Memory II
In the design of all computers, semiconductor memories
are used as primary storage for data and code.
They are connected directly to the CPU and they are the
memory that the CPU asks for information (code or data).
Among the most widely used are RAM and ROM.
Memory Capacity
The number of bits that a semiconductor memory chip
can store is called its chip Capacity (bits or bytes)
Memory Organization

6. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Semiconductor Memory III
Each memory chip contains 2N locations where N is the
number of address pins on the chip.
Each location contains M bits, where M is the number of
data pins on the chip.
The entire chip will contain 2N x M bits.
Example: Memory organization of 4K x 4, 212 = 4096
locations, each location holding 4 Bits (so N=12 and
M=4)
Memory Speed (access time)

7. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Introduction to Memory Interfacing
1 Semiconductor Memory Fundamentals
2 Memory Types
3 Memory Structure and its requirements
4 Memory Decoding
5 Examples on Memory Interfacing

8. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
ROM I

9. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
ROM II
1 ROM (Read Only Memory)
ROM is the type of memory that does not lose its contents
when power is turned off. It is also called nonvolatile
memory.
2 PROM (Programmable Memory)
User programmable (one-time programmable) memory.
If the information burned into PROM is wrong, it needs to
be discarded since internal fuses are blown permanently.
Special equipment needed: ROM burner or ROM
programmer.
3 EPROM (Erasable Programmable ROM) 2,000 times
Allows making changes in the contents of PROM after it is
burned.
One can program the memory chip and erase it thousands
of times.
Erasing its contents can take up to 20 minutes; the entire
chip is erased.

10. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
ROM III
All EPROM chips have a window that is used to shine
ultraviolet (UV) radiation to erase its contents.
Also referred to as UV-EPROM.
4 EEPROM (Electrically Erasable ROM) 500,000 times
Method of erasure is electrical.
Moreover, one can select which byte to be erased.
Cost per bit is much higher than for UV-EPROM.
5 Flash Memory EPROM
First, the process of erasure of the entire contents takes
less than a second, or one might say in a flash, hence its
name: flash memory.
When flash memory’s contents are erased, the entire
device is erased.
Even though flash memories are writeable, like EPROM’s
they find their widest use in microcomputer systems for
storage of firmware.

11. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Random Access Memory I

12. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Random Access Memory II
1 SRAM (Static RAM)
Storage cells are made of flip-flops and therefore they do
not require refreshing to keep their data.
A cell handling one bit requires 6 or 4 transistors each,
which is too many.
SRAMS are widely used for cache memory and
battery-backed memory systems.
2 DRAM (Dynamic RAM)
Uses MOS capacitors to store a bit
Requires constant refreshing due to leakage (every 2ms –
4ms).

13. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Random Access Memory III
Advantages
a. High density (capacity),
b. Cheaper cost per bit
c. Lower power consumption.
Disadvantage
a. While it is being refreshed, data cannot be accessed
b. Larger access times
c. Too many pins due to large capacity

14. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Memory Device

15. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Introduction to Memory Interfacing
1 Semiconductor Memory Fundamentals
2 Memory Types
3 Memory Structure and its requirements
4 Memory Decoding
5 Examples on Memory Interfacing

16. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Memory structure of RAM and ROM

17. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Basic Concept of Memory Interfacing
The memory interfacing requires:
Select the chip (Enable CS).
Identify the register.
Enable the appropriate buffer ( Read or Write)
Microcontroller based system include memory devices and the
input – output devices. It is important to note that
microcontroller can communicate (Read or Write) with only
one device at a time, since the address, data and control lines
are common for all the devices.
In order to communicate with memory or IO device, it is
necessary to decode the address from the microcontroller.

18. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Introduction to Memory Interfacing
1 Semiconductor Memory Fundamentals
2 Memory Types
3 Memory Structure and its requirements
4 Memory Decoding
5 Examples on Memory Interfacing

19. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Absolute or Full Decoding

20. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Partial or Linear Decoding

21. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Introduction to Memory Interfacing
1 Semiconductor Memory Fundamentals
2 Memory Types
3 Memory Structure and its requirements
4 Memory Decoding
5 Examples on Memory Interfacing

22. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Example
1
Show the interfacing of an 8051 microcontroller with 8K bytes
of data ROM.
Answer
1

23. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing

24. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Example
2
Show the interfacing of an 8051 microcontroller with 8K bytes
of data ROM and 8K bytes of program ROM.
Answer
2

25. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing

26. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Example
3
Show the interfacing of an 8051 microcontroller with 4K bytes
of data RAM with 8051 Microcontroller.
Answer
3

27. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing

28. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Example
4
Show the interfacing of an 8051 microcontroller with 16K bytes
of data RAM with 8051 Microcontroller. Assume the starting
address of 16KB data RAM is 8000h.
Answer
4

29. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing

30. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Example
5
Show the interfacing of an 8051 microcontroller with 8K bytes
of program memory, 8K bytes of data ROM and 8K bytes of
data RAM. Show the complete address mapping. Use 74LS138
3 to 8 decoder for the generation of chip select.
Answer
5

31. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Example
6
Show the interfacing of an 8051 microcontroller with 16K
Bytes of data ROM and 16K Bytes of data RAM

32. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Answer
6

33. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing

34. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Example
7
(a) Design the interfacing system for the Microcontroller 8051
with 256K Bytes of SRAM. Assume that available IC is 64K
Bytes of SRAM.
(b) Write an assembly language program to read 10 bytes from
memory location 20000h and store the contents in the internal
memory location from 30h.
Answer
7

35. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing

36. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing

37. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Example
8
Show the interfacing of an 8051 microcontroller with 4K bytes
of data ROM and 8K bytes of data RAM.
Answer
8

38. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing

39. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Example
9
Show the interfacing of an 8051 microcontroller with 8K bytes
of data ROM and 8K Bytes of data RAM using partial
decoding techniques.
Answer
9

40. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing

41. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Example
10
Show the interfacing of an 8051 microcontroller with 16K bytes
of data RAM using the available memory IC 6164.
Answer
10

42. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing

43. Memory
Interfacing
with Micro-
controller
8051
Dr. Nilesh
Bhaskarrao
Bahadure
Semiconductor
Memory
Fundamentals
Memory Types
Memory
Structure and
its
requirements
Memory
Decoding
Examples on
Memory
Interfacing
Thank you
Please send your feedback at nbahadure@gmail.com
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Main Slide