Question

1. (6 Marks) Using the single bus architecture provided below (as seen in class also), write the sequence of micro-code instructions for doing the following tasks (as given by points a), b) and c)). You do not have to worry about timing in this question. For memory reads/writes, assume the operation finishes in 1 clock cyclıe (no timing issues). For each micro-code you provide, comment on what you are accomplishing The following table gives ALU functions operating on numbers in two's complement format ALU Code Functiorn Output zero Add the contents of Y and other data value (ALUin). * Increment the value stored in Y by 1.* Subtract Y by the other data value (ALUin).* 001 011 * Note that this does NOT change the value stored in the Y register. Instead, the result simply appears on the output pins of the ALU c) Add the contents of the MDR and AC and write the result back to memory whose address is already stored in the MAR register. CPU Structure IR Control R Unit W PCin Rin Rout PC Cout MDRin Other Signals MDR Memory MARinMDRo MAR ACin MARout AC Yin control points- controlled by CU Yout ACout ALUin ALU ALU COD Zin Zout Internal CPU Bus Here is a sequence of micro-instructions to add the content of the AC and the MDR and store the result back into the AC 00 000 10 0 0 0 0 0 0 1 0 0 0 Yi You IRi IRou 2) 001 010l0 110 0 0 00 011 0 010 0 ALU MARIMARoMDRi MDRouACi ACou Rea Writ PCi PCouALUiZi Zou Yi You Ri Rou n td en tn ALU MARiMARoMDRi MDRouACi ACou Rea Writ PCi PCou ALUi Zi Zou Yi You IRi Rou

Answer 1

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