Question

(2+2+1 5 points) Problem 10.1: simple cpu machine code = The following program has been written for the simple central processing unit introduced in class. The table below shows the initial content of the 16 memory cells. The first column denotes the memory address. Machine Code Assembly Code Description 001 1 0001 0 010 0 1111 1 001 1 0000 3 101 1 0100 110 1 0110 4 111 1 0000 5 6 001 0 001 1 100 1 0001 7 8 010 0 0011 9 001 0 1111 011 0 111 10 11 010 0 1111 12 110 1 0010 13 000 0 0000 no instruction / data, initialized to 0 no instruction/ data, initialized to 0 no instruction / data, initialized to 0 14 000 0 0000 15 000 0 0000 a) Explain what the instructions are doing by filling in the assembly code column. Add meaningful text to the description column to describe the action performed by an instruction b) Explain how the program proceeds with its calculation. Describe the execution of the program Which cells change and what is the purpose of the changes? What is the result left in memory cell 15 when the program stops execution? c) Can you describe in general terms what the program is doing using a mathematical expres- sion?

Answer 1

#	MACHINE CODE	ASSEMBLY CODE	DESCRIPTION
0	00110001	31	LXI SP- This instruction initializes the top of the stack,and initializes the stack pointer.
1	01001111	4F	MOV C,A - Moves data in A register to C register.
2	00110000	30	SIM- Set Interrupt mask- It reads the status of interrupts.
3	10110100	B4	ORA H- Logical bitwise operation of register H with Accumalator data.
4	11010110	D6	SUI DATA- Subtract imidiately data given in instruction from the accumalator.
5	11110000	F0	RP- Sequencing of program is transferred to a 16 bit address
6	00100011	23	INX H- Increments value in HL pair by 1.
7	10010001	91	SUB C- Subtracts the value in c register from the accumalator
8	01000011	43	MOV B,E- Moves data in C register to B register
9	00101111	2F	CMA- Complements the data in register A
10	01101111	6F	MOV L,A -Move data in register A to register L.
11	01001111	4F	MOV C,A -Move data in register A to register C
12	11010010	D2	JNC Label- Jump to a new specified address if the carry flag is not set.
13	00000000		LSB part of jump address.
14	00000000		MSB part of jump address.
15	00000000