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Architecture and pin diagram of 8085

  8085 MICROPROCESSOR 1.1 Hardware Architecture Control Unit Generates signals within Microprocessor to carry out the instruction, which has been decoded. In reality causes certain connections between blocks of the uP to be opened or closed, so that data goes where it is required, and so that ALU operations occur. Arithmetic Logic Unit The ALU performs the actual numerical and logic operation such as „add‟ , „subtract‟ , „AND‟ , „OR‟ , etc. Uses data from memory and from Accumulator to perform arithmetic. Always stores result of operation in Accumulator. Registers The 8085/8080A-programming model includes six registers, one accumulator, and one flag register, as shown in Figure. In addition, it has two 16-bit registers: the stack pointer and the program counter. The 8085/8080A has six general-purpose registers to store 8-bit data; these are identified as B,C,D,E,H, and L as shown in the figure. They can be combined as register pairs...

8085 Memory Interface

8085 Memory Interface Terminology which are used. Memory are made up of registers. Each register consists of one storage location.   Each location consists of an address.  The number of storage locations from few hundreds to several mega or giga locations.   The total number of memory storage is called memory capacity and measured in Bytes.  Each register consists of storage element (FF, capacitor for semiconductor)  A storage element is called cell.  The data could be read from or written to memory. Memory Structure and its requirements As mentioned earlier, read/write memories consist of an array of registers, in which each register has unique address. The size of the memory is N x M as shown below where N is the number of registers and M is the word length, in number of bits1 Summarizes capacity with address Memory Capacity Address lines required 1 k = 1024 memory locations ...