7.1 Program Analysis 1. Analyze the following program. Examine the instructions one by one, inspecting the values from the AC and the memory to understand what the program does. Write a simple pseudo code to describe the program. Give the following names to the variables stored at the memory addresses A0 - A3 (hex): 2. Address A0 A1 Name of variable Counter Note that X, Y and Z are pointers. 3. 4. What does calculate this program? Why is practical to use in this program memory - reference instructions with indirect addressing in other words, instructions which use pointers)? % PROGRAM IS IN the RANGE Of ADDRESSES 00 TO 7F % 00:04; % LDA (direct) % 01: a0; % from address a0 % 02:42; CA % 03:08; % STA (direct) % 04: a0; % AC to address a0 % 05:20; % 1SZ (direct) % 06: a0; % counter stored at a0 % 07:10; % BUN (direct) % 08:20; % to address 20 % 09:60; HLT % 20:84; % LDA (indirect) % 21: a1; % the number pointed to by the memory location a1 % 22:82; % ADD (indirect) % 23: a2; % the number pointed to by the memory location a2 % 24:88; % STA (indirect) % 25: a3; to the memory location pointed to by a3 26:04; % LDA (direct) % 27: a1; % from the address a1 % 28:50; Inc % 29:08; % STA (direct) % 2a: a1; AC to the memory address al 2b : 50; Inc % 2c: 08; % STA (direct) % 2a: a2; % store AC to the memory address a2 % 7 % STA (direct) % % send AC to the memory address a3 % % BUN (direct) % % to the memory address 05 % % DATA ARE FOUND AT ADDRESSES 80 TO FF % 2f: 08; 30: a3; 31:10; 32:05; 80: 01; 81: 01 a0: 0a; a1: 80; a2: 81; a3: 82: loop counter, which will be done 10 times % pointer to the first number to be added % % pointer to the second number to be added % inter to memory location where result will be stored %