Internal Architecture of 8088 Microprocessor:
Figure 5.24 shows the Internal Architecture of 8088 Microprocessor. The set of registers of 8088 is approximately same as that of 8086. The architecture of 8088 is same as 8086 architecture, but there are two changes. The 8088 has a 4-byte instruction queue in place of 6-byte instruction queue in 8086 and the data bus of 8088 is 8-bit. The other function blocks are the same as the 8086 processor.
The Architecture of 8088 Microprocessor has 1 Mbyte addressing capability and it has a 20-bit address or 20 addressing lines. The concept of segmented memory and the computational method of physical address are used in the 8088 processor without any change and it is same as the 8086 processor. The memory organization and addressing methods of 8088 are similar to 8086. There is no concept of even-address bank and odd-address bank of memory in 8088. Therefore, the complete memory is consistently addressed as a bank of 1Mbyte memory locations with the help of the segmented memory conception.
As the data bus is 8-bit, the 8088 can access only a byte at a time. Therefore, the speed of operation of 8088 will be reduced as compared to 8086, though internal data bus of 8088 is 16 bits and it can process the 16-bit data internally. Due to change in address and data bus structure, the timing diagrams of 8088 are different from 8086.