Question

A C program has been compiled into the Atmel AVR assembly language. The following instruction, which is located at address 0x002A, is executed:

i.) What is the binary value contained in the instruction register (IR) when the instruction is executed?

ii.) What is the hexadecimal value of the program counter (PC) when the instruction is executed?

iii.) If register r1 = 0x40 and register r2 = 0x02 prior to executing the instruction, what are the contents of r1 and r2 after the instruction has executed?

(b) A C program has been compiled into the Atmel AVR assembly language. The following instruction, which is located at address Ox002A, is executed: add ri, r2 The syntax and behaviour of the add instruction is defined as follows: Syntax add Rd, Rr Program counter PC + PC +1 Add without Carry Operands Operation 0<d<31,0 <r<31 Rd - Rd + Rr Opcode Flags 0000 11rd dddd rrrr HS, V, N, Z, C (i) [4 marks] What is the binary value contained in the instruction register (IR) when the instruction is executed? (ii) [1 mark] What is the hexadecimal value of the program counter (PC) when the in- struction is executed? (iii) [2 marks] If register r1 = 0x40 and register r2 = 0x02 prior to executing the instruc- tion, what are the contents of r1 and r2 after the instruction has executed? TURN OVER

Answer 1

add= O o oo I оо00] O O o O 2 O o O O OID PcPet size r nstlucHon = 2. oxo002A t ox) Pc = C ox 4 2- DX O2 add охо O X 2