3. Internal Architecture of 8085 Microprocessor

3.1 Register Array

8085 Microprocessor consists of six registers, one accumulator and a flag register. The typical architecture is shown in figure 3.2.2. There are six general-purpose registers B, C, D, E, H, and L, each having capacity to store 8 bit data. They are combined as BC, DE, HL to perform 16 bit operations. In addition to this Register array, two 16 bit registers viz. stack register and program counter are provided. As discussed in the earlier lecture, the ‘program counter' is employed to sequence the execution of instructions. It always points to the memory address from which the next byte is to be fetched. Stack Pointer points to the memory location in R/W (Read and/or write) memory. It is also termed as a ‘stack'.

 

Figure 3.2.2 Architecture of 8085 microprocessor