Question

what is a timer? draw and explain the special function of the timers in 8051?​

Answer 1

8051 Microcontroller Special Function Registers (SFRs)

April 6, 2021

By Ravi Teja (Embedded Engineer)

In the previous 8051 Microcontroller Tutorial, we have seen the Instruction Set and Addressing Modes. In this tutorial, we will take a look at the 8051 Microcontroller Special Function Registers or SFRs.

If you remember from the 8051 Microcontroller Memory Organization Tutorial, the internal RAM or Data Memory of the 8051 Microcontroller is divided in to General Purpose Registers, Bit Addressable Registers, Register Banks and Special Function Registers or SFRs.

The 8051 Microcontroller Special Function Registers are used to program and control different hardware peripherals like Timers, Serial Port, I/O Ports etc. In fact, by manipulating the 8051 Microcontroller Special Function Registers (SFRs), you can assess or change the operating mode of the 8051 Microcontroller.

As a reminder, the following image shows you the basic structure of 8051 Microcontroller’s Internal RAM.