Memory interfacing is used to provide more memory space to accommodate complex programs for more complicated systems. In intel microprocessor 8086, what is meant by segment register. The address value of 15 bits is 5 digit octal numbers and data is of 12 bits word in 4 digit octal number. Later microprocessors 8086 and 68000 were designed with. Pdf microprocessor engineering lecture notes third class electrical engineering. Let us discuss sta instruction in detail for better understanding. Interfacing is of two types, memory interfacing and io interfacing. Types of memories which are most commonly used to interface with 8085 are ram. Lecture note on microprocessor and microcontroller theory. The associative memory stores both address and data. Types of memories which are most commonly used to interface with 8085 are ram, rom, and eeprom.
Microprocessor is the brain of computer, which does all the work. Microprocessors were first introduced in early 1970s. Lecture note on microprocessor and microcontroller theory vssut. Todays microprocessors include several circuits to make memory. It is a computer processor that incorporates all the functions of cpu central processing unit on a single ic integrated circuit or at the most a few ics.
In storeprogram concept, programs or instructions are sequentially stored in the memory locations that are to be executed. For example, same of 8085 a instructions that can be used for input from memory mapped io ports. Microprocessor io interfacing overview tutorialspoint. It is possible to address an io port as if it were a memory location. Differences between isolated io and memory mapped io. Memory mapping is the translation between the logical address space and the physical memory. For this, both the memory and the microprocessor requires some signals to read from and write to registers. The basic concepts are similar to interfacing of output devices.
To do any task using a microprocessor, it is to be programmed by the user. Memorymapped io in 8085 microprocessor tutorialspoint. What is memory mapping in microprocessor based systems. This memory map topic is very important for understanding computer architecture. Prepared by radu muresan 15 microcontroller concepts a. A cpu address of 15 bits is placed in argument register and the. When we are executing any instruction, we need the microprocessor to access the memory for reading instruction codes and the data stored in the memory. Consider the problem of implementing the following memory map for an 8bit microprocessor based system figure 10. Microcontroller microprocessor with builtin memory and ports and can be. Mapping is important to computer performance, both locally how long it takes to execute an instruction and globally. For example, the chip select for u4 has to generate the. Every ece engineer must know the microprocessor memory map. The allocation of the memory is called a memory map.
The transformation of data from main memory to cache memory is called mapping. Figure 23 illustrates the format of a segment descriptor. The 20bit address of the 80868088 allows 1m byte of 1024 k bytes memory space with the address range 00000fffff. Memory map and addresses in 8085 tristate logic devices.
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