Differences between 8086 and 8088 microprocessors

Differences Microcontroller Microprocessor 8086 8088

A microprocessor can be defined as an electronic component of a computer system that executes the instructions to perform tasks involved in computer processing. It is the most fundamental unit of computer that executes all the functions of a CPU. Till date, several types of microprocessors have been developed. But in this article, we will learn about the two earliest microprocessors, namely, 8086 and 8088 microprocessors. Both 8086 and 8088 microprocessors are widely used in embedded systems due to their various important and unique features.

This articles is primarily meant for explaining the major differences between 8086 and 8088 microprocessors. But before comparing 8086 and 8088 microprocessors, it is important to learn their basics so it becomes easier to understand the differences between them.

What is 8086 Microprocessor?

8086 Microprocessor is an enhanced version of 8085 Microprocessor that was designed by Intel in 1976. It is a 16-bit Microprocessor having 20 address lines and16 data lines that provides up to 1MB storage. It consists of powerful instruction set, which provides operations like multiplication and division easily.

8086 microprocessors support two modes of operation, i.e. maximum mode and minimum mode. The maximum mode is suitable for system having multiple processors, whereas the minimum mode is suitable for system having a single processor.

8086 microprocessors have an instruction queue, which can store six instruction bytes from the memory resulting in faster processing. Historically, 8086 microprocessors were the first 16bit processor having 16-bit ALU, 16-bit registers, internal data bus, and 16-bit external data bus resulting in faster processing.

What is 8088 Microprocessor?

8088 Microprocessor was also developed by Intel in the year of 1979. The 8088 microprocessor has an architecture similar to Intel’s 8086 microprocessor. It has an 8-bit external data bus, thus it requires two cycles to process a string of 16-bit data. The 8088 microprocessor was developed by using highdensity, short channel metal-oxide semiconductor technology. 8088 microprocessors came in two variants: 40 Pins and 44 Pins.

8086 microprocessors have a clock frequency in the range of 5 to 10 MHz. They have 16-bit registers, 20-bit address bus, and 16-bit external data bus.

Difference between 8086 and 8088 Microprocessors

The following table highlights the major differences between 8086 and 8088 microprocessors −

Parameter	8086 Microprocessor	8088 Microprocessor
Data and Address Bus	In case of 8086 MPU, the data bus is of 16 bits and the address bus is of 20 bits.	In an 8088 MPU, the data bus is of 8 bits and the address bus is of 20 bits.
Processing	8086 has 3 available clock speeds (5 MHz, 8 MHz (8086-2) and 10 MHz (8086-1)).	8088 has 2 available clock speeds (5 MHz, 8 MHz)
Memory capacity	8086 has the memory capacity of 512 kB.	In 8088, memory capacity is implemented as a single 1 MX 8 memory banks.
Signal Type	8086 has memory control pin (M/IO) signal.	8088 has complemented memory control pin (IO/M) signal of 8086.
Current Supply	8086 draws a maximum supply current of 360 mA.	8088 draws a maximum supply current of 340 mA.
Word Length	8086 microprocessors can read or write either an 8-bit or 16-bit word at a time.	8088 microprocessors can read only an 8-bit word at a time.
Instruction Queue	8086 microprocessors have an instruction queue of 6-bytes.	8088 microprocessors have an instruction queue of 4-bytes. It is because the 8088 microprocessor can fetch only 1-byte at once.
I/O Voltage Level	In 8086 microprocessors, the input/output voltage level is measured at 2.5 mA.	In 8088 microprocessors, the input/output voltage level is measured at 2 mA.

Conclusion

The most significant difference between the 8086 and 8088 microprocessors is that 8086 is a 16-bit microprocessor, while 8088 is an 8bit microprocessor. Both 8086 and 8088 are the earliest microprocessors developed by Intel, however they are still widely used in embedded systems due to their various important and unique features.