Computer System Architecture Lab

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Question Based on guideline.

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Question 1 of guideline

1. Create a machine based on the following architecture: Register Set

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2. Create the micro operations and associate with instructions as given in the chapter (except interrupts). Design the register set, memory and the instruction set. Use this machine for the assignments of this section. 

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2.      Create the micro operations and associate with instructions as given in the chapter (except interrupts). Design the register set, memory and the instruction set. Use this machine for the assignments of this section. 

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3.      Create a Fetch routine of the instruction cycle. 

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4.      Simulate the machine to determine the contents of AC, E, PC, AR and IR registers in  hexadecimal after the execution of each of following register reference instructions: 

a.   CLA            e. CIR i. SNA

b.  CLE             f. CIL j. SZA

c.   CMA           g. INC k. SZE

d.  CME           h. SPA             l. HLT 

Initialize the contents of AC to (A937)₁₆, that of PC to (022)₁₆ and E to 1. 

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5.      Simulate the machine for the following memory-reference instructions with I= 0 and address part = 082. The instruction to be stored at address 022 in RAM. Initialize the memory word at address 082 with the operand B8F2 and AC with A937. Determine the contents of AC, DR, PC, AR and IR in hexadecimal after the execution. 

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a.   ADD           f. BSA

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b.  AND           g. ISZ

c.   LDA

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d.  STA

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e.   BUN

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6.      Simulate the machine for the memory-reference instructions referred in above question with I= 1 and address part = 082. The instruction to be stored at address 026 in RAM. Initialize the memory word at address 082 with the value 298. Initialize the memory word at address 298 with operand B8F2 and AC with A937. Determine the contents of AC, DR, PC, AR and IR in hexadecimal after the execution. 

       

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7.      Modify the machine created in Practical 1 according to the following instruction format: 

a.       The instruction format contains a 3-bit opcode, a 1-bit addressing mode and a 12-bit address. There are only two addressing modes, I = 0 (direct addressing) and I = 1  (indirect addressing). 

b.      Create a new register I of 1 bit. 

c.       Create two new microinstructions as follows : 

i. Check the opcode of instruction to determine type of instruction (Memory  Reference/Register Reference/Input-Output) and then jump accordingly.  ii. Check the I bit to determine the addressing mode and then jump accordingly. 

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