Question

8051 has _______ special function registers.
1. 21
2. 8
3. 16
4. 11

Answer 1

Correct Answer - Option 1 : 21

Explanation:

Microcontroller 8051:

• Microcontrollers are embedded inside devices to control the action and feature of a product or equipment.
• So they can also be referred to as embedded controllers. They run one specific program and are dedicated to a single task.
• They are low power devices with dedicated input devices and small LED or LCD display outputs.
• Microcontroller 8051 is designed by Intel in 1981.
• It is an 8-bit microcontroller. It is built with 40 pins DIP (Dual inline package), 4 KB of ROM storage and 128 bytes of RAM storage, two 16-bit times.
• It consists of four parallel 8-bit parts, which are programmable as well as addressable as per the requirement.

FR’s (special function registers):

• There are 21 SFR’s (special function registers) in microcontroller 8051. The SFR is the upper area of addressable memory, from address OX80 to OXff.
• These SFR’s contain all peripherally related register like P0, P1, P2, P3, timers or counters, serial part and interrupt related registers. Hence option (1) is the correct answer.