Computer instruction
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1. The document discusses the topics of computer instructions, timing and control, and the instruction cycle for a basic computer. 2. It describes the three instruction code formats used - memory reference, register reference, and input/output. Memory reference instructions use bits to specify an address and addressing mode. Register reference instructions specify an operation on the accumulator register. 3. The instruction cycle consists of four phases - fetch an instruction, decode the instruction, read the effective address if needed, and execute the instruction.
![[object Object],The basic computer has three instruction code formats which are :- ,[object Object], A memory – reference instruction uses 12 bits to specify an address and 1 bit to specify the addressing mode I. I is equal to 0 for direct address and to 1 for indirect address ,[object Object], A register reference instruction specifies an operation on or a test of the AC register .An operand from the memory is not needed therefore the other 12 bits are used to specify the operation to be executed. ,[object Object], An input-output instruction does not need a reference to memory and is recognized by operational code 111 with a 1 in the left most bit of the instruction the remaining 12 bits are used to specify the type of input output operation or test performed.](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
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Computer instruction
- 1. PRESENTATIONTOPICS :1. COMPUTER INSTRUCTIONS.2.TIMING & CONTROL.3. INSTRUCTION CYCLE. BY :- PAAWAN GUPTA 109-38126 B.SC.(C.SCIENCE)2ND YEAR
- 6. Input-Output instructionI=0 : Direct, I=1 : Indirect
- 13. THaNk you…….