8089 pin diagram || pin details

 Register Section of 8085

At first we will see some important configuation of 8085 

Accumulator - 8bit

data bus - 8bit

address bus - 16bit

program counter - 16bit 

stack pointer - 16 bit 

BC DE HL -  Each has 8bit (by pairing they perform as 16 bit)

>> Accumulator : Accumulator 8 - bit register ,used to perform Arithmatic(Addition, Substract..etc) and Logical Operation(OR, AND , NOT..etc) .It  is used to store the result of these operation.

>>GPR(General Purpose Resister) : The 8085 has six 8 bit GPR , name B,C,D,E,H,L. Thay used for storing the operands> Temporarely during the execution of the instruction . These resgister can be used single or can be concatenated to form three 16 bit register B-C, D-E, H-L, while storing 16 bit in the register payer the higher order byte of the data/address is store in the first register(b/D/H) and lower order data/ address is store in the second register(C/E/L)

>> SFR(Special Function Register) : 

• FLAG register (8-bit) : Flag register is used for storing significant information regarding the final result of an instruction . This informations are used for decision making. 

The informations are store in the 5 bit o the register in the form of FLAG. while the other 3 bits insignificant . The significant bit or flags are - (i) Sign flag (ii) zero flag (iii) Auxulary  Carry Flag (iv) Parity flag (v) carry flag 

(i) Sign Flag : If the final result store in the Accumulator in Negetive . Then sign flagis set(S=1), other wise (positive) sign flag is reset(S=0).

(ii) Zero Flag : If the final result obtain after execution of an instruction is Zero then the zero flag is set(z=1)

(iii) Auxulary Carry Flag : Auxulary flag is set if an overflow occure out of  B 3 of an Accumulator. It is used in BCD(Binary Codded Decimal) 

(iv) Parity Flag: If the number of ones after execution in the accumulator is even then parity flag is set.

(v) carry Flag: When over flow occures out of B7 and borrow is occur then CY or carry flag is set.

>> rogram counter : It is a 16 bit register. Which is used for holding the address of next instruction to be executed in a program sequence . The processor update the precontain Automatically .After it has fetched one instruction for execution.

>> Stack Pointer :  Stac Pointer is usually an array of memory location in the Ram which are used for storing temporary information in LIFO manner . 

Stack Pointer is decremented s time data is pushed into the stack and is incremented is type when data is popped or removed from the stack.

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