The table shows assembly language instructions for a processor that has one general purpose register, the Accumulator (ACC). Instruction Table: Label | Opcode | Operand | Explanation ---|---|---|--- | LDM | #n | Load the number n to ACC | LDD | <address> | Load the contents of the given address to ACC | LDI | <address> | The address to be used is at the given address Load the contents of this second address to ACC | ADD | <address> | Add the contents of the given address to the ACC | STO | <address> | Store the contents of the ACC at the given address <label>: | <data> | Gives a symbolic address <label> to the memory location with the contents <data>. <label> can be used in place of <address> # denotes a denary number, e.g. #123

1. (a)The address 500 contains the value 100 and the address 100 contains the value 20. State the addressing mode and the contents of ACC after each instruction has been executed. LDM #500 Addressing mode Contents of ACC LDD 500 Addressing mode Contents of ACC LDI 500 Addressing mode Contents of ACC[3]
2. (b)Use only the given instruction set to write assembly language code to: • use the constant 20 which needs to be stored • add this constant to the value stored in the address contained in the variable Y • store the result in variable Z. Instruction Table (to be completed): Label | Opcode | Operand ---|---|---[7]