Differences Between 8253 and 8254

Both 8253 and 8254 are Programmable Interval Timers (PTIs) which are designed to perform different functions like time and counting by using triple 16-bit registers. Both 8253 and 8254 have 2 input pins and 1 output pin. In this article, we are going to discuss the Differences Between 8253 and 8254 in detail.

Table of Content

  • What is 8253 ?
  • Block Diagram For 8253

  • What is 8254 ?
  • Applications
  • Block Diagram For 8254

  • Differences Between 8253 and 8254

What is 8253 ?

The Intel 8253 is a programmable interval timer or PIT chip. It performs counting and timing functions using three 16-bit counters for the microcomputers. Each counter has two specific input pins and one output pin. These can be programmed to perform the counting process in a binary mode. The modes of the 8253 determine how these counters work and also regulate the one output pin as well.

Advantages

Here are the advantages and disadvantages of 8253 mentioned below.

  • Versatility : Both chips offer three independent 16-bit counters that can be programmed for a wide range of timing and counting applications.
  • Programmability : The chips allow programmers to set the operating mode of each counter independently, providing flexibility in generating various timing and counting operations.
  • Limited Resolution : The 16-bit counters have a limited resolution compared to modern timers, which may not be sufficient for applications requiring very precise timing.

Disadvantages

Here are the disadvantages a mentioned below.

  • Complexity : Programming the chips can be complex, especially for users unfamiliar with their operation and various modes.
  • Limited Features : Compared to modern timer peripherals integrated into microcontrollers, the 8253 lack advanced features such as PWM (Pulse Width Modulation) generation and input capture.

Block Diagram For 8253

Here is the Block Diagram For 8253 microprocessor as mentioned below.

Block Diagram For 8253 Microprocessor

What is 8254 ?

8254 Programmable Timer. The system is particularly used for timing control applications in different microcomputing systems. The timer has 3 independent counters capable of handling the clock inputs up to almost 10 MHz with a 16-bit size for each counter. The timer can work with the +5V power supply with 24-pin signals as well.

Advantages

Here are the advantages and disadvantages of 8254 mentioned below.

  • Versatility : Both chips offer three independent 16-bit counters that can be programmed for a wide range of timing and counting applications.
  • Programmability : The chips allow programmers to set the operating mode of each counter independently, providing flexibility in generating various timing and counting operations.
  • Limited Resolution : The 16-bit counters have a limited resolution compared to modern timers, which may not be sufficient for applications requiring very precise timing.

Disadvantages

Here are the disadvantages mentioned below.

  • Complexity : Programming the chips can be complex, especially for users unfamiliar with their operation and various modes.
  • Limited Features : Compared to modern timer peripherals integrated into microcontrollers, the 8254 lack advanced features such as PWM (Pulse Width Modulation) generation and input capture.

Applications

Here are the applications of 8254 mentioned below.

  • Embedded systems for timing critical tasks
  • Event scheduling
  • Real-time clock (RTC) functions
  • Industrial control systems for timing various processes
  • Controlling machinery
  • Synchronizing operations

Block Diagram For 8254

Here is the Block Diagram For 8254 microprocessor as mentioned below.

Block Diagram For 8254 microprocessor

Differences Between 8253 and 8254

Here are the major Differences Between 8253 and 8254 as mentioned below.

Aspects 8253 8254
Manufacturing Technology NMOS HMOS
Maximum Clock Frequency 2.6 MHz 10 MHz
Operating Voltage 5V 5V
Power Consumption Higher compared to 8254 Lower compared to 8253
Binary/BCD Mode Both modes available Both modes available
Counter Size 16-bit counters 16-bit counters
Number of Counters 3 3
Mode Compatibility Compatible with Intel 8255 Compatible with Intel 8255
Read/Write Operations Read/Write operations are sequential Supports Read Back command
Control Word Format Single control word format Enhanced control word format
Counter Latch Command Available Available
Operating Modes 6 Modes 6 Modes
Initialization Time Longer initialization time Shorter initialization time
Gate Control Software control Software control
Input Pin Names CLK, GATE, OUT CLK, GATE, OUT
Operating Temperature Range Standard commercial range Industrial range available
Package Types DIP, PLCC DIP, PLCC
Reset Behavior Not explicitly defined Defined reset behavior
Maximum Count 2^16 – 1 2^16 – 1
Availability Legacy component Enhanced and widely used

Conclusion

In the conclusion, we have learnt about the differences between 8253 and 8254 with respect to the working, applications and manufacture. In terms of power consumption, 8253 consumes higher as compared to 8254.But both 8253 and 8254 avails both Binary and BCD Modes.

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FAQs – Differences Between 8253 and 8254

Why is 8254 used?

8254 Programmable Timer is used for timing control applications in microcomputer systems. The design is capable of generating accurate time delays under software control.

What is the difference between 8253 and 8254 microprocessors?

The 8254, described as a superset of the 8253 with higher clock speed ratings, has a “preliminary” data sheet in the 1982 Intel “Component Data Catalog”.

What is 8253 used for?

The specialty of the 8253 counters is that they can be easily read on line without disturbing the clock input to the counter. This facility is called as “on the fly” reading of counters, and is invoked using a mode control word.

How many pins does 8253 have?

Intel 8253 is a 24-pin programmable IC available. IC has three counters which work independently and whose width is of 16-bits.

What is the role of 8253 8254 pit?

The Intel 8253 and 8254 are Programmable Interval Timers (PTIs) designed for microprocessors. a pulse that can be used to interrupt the CPU.



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