ICT 114 Computer Architecture

PLEASE PROVIDE EXPLANATION

This question is based on the EASY68K simulated processor. Assume the contents of all data and address registers are equal to zero before the start of the program. All numbers are in hexadecimal. Demonstrate how instructions of the program are executed by using the E114 Processor Instruction Set of the EASY68K simulator. Figure Q3 shows a program segment based on the course's simulated processor. The program is to determine the average of a series of integers stored in an array. Assume the average is an integer, ignoring the fractional parts. ORG START MOVE MOVE.B MOVEL LOOP ADD.B SUB.B BNE LSR MOVE.B STOP S1000 #S2000, AO #808, DO #SO, DI (A0+, DI #S01, DO LOOP #$03, D1 Logical Shift Right by 3 places DI, $2050 #$2700 Figure 03 Note: Instruction Logical Shift Right (LSR) shifts the contents of register D1 by 3 bits to the RIGHT (b) Identify the addressing mode used in each of the following instructions. (1) MOVE.B #$08, DO (ii) ADD.B (A0+, DI (iii) LSR #$03, D1 (iv) MOVE.B D1, $2050 (4 marks) The program includes a loop. Which register is being used as a loop counter and how many times in total will the set of instructions within the loop be executed? (2 marks) From which instruction(s) do you deduce the answers for Q3(b)? (2 marks) The loop picks up successive data items from a block of locations in data memory. What are the lowest and highest addresses in Hex) of the locations in this block? (2 marks) (d) This question is based on the EASY68K simulated processor. Assume the contents of all data and address registers are equal to zero before the start of the program. All numbers are in hexadecimal. Demonstrate how instructions of the program are executed by using the E114 Processor Instruction Set of the EASY68K simulator. Figure Q3 shows a program segment based on the course's simulated processor. The program is to determine the average of a series of integers stored in an array. Assume the average is an integer, ignoring the fractional parts. ORG START MOVE MOVE.B MOVEL LOOP ADD.B SUB.B BNE LSR MOVE.B STOP S1000 #S2000, AO #808, DO #SO, DI (A0+, DI #S01, DO LOOP #$03, D1 Logical Shift Right by 3 places DI, $2050 #$2700 Figure 03 Note: Instruction Logical Shift Right (LSR) shifts the contents of register D1 by 3 bits to the RIGHT (b) Identify the addressing mode used in each of the following instructions. (1) MOVE.B #$08, DO (ii) ADD.B (A0+, DI (iii) LSR #$03, D1 (iv) MOVE.B D1, $2050 (4 marks) The program includes a loop. Which register is being used as a loop counter and how many times in total will the set of instructions within the loop be executed? (2 marks) From which instruction(s) do you deduce the answers for Q3(b)? (2 marks) The loop picks up successive data items from a block of locations in data memory. What are the lowest and highest addresses in Hex) of the locations in this block? (2 marks) (d)