Cmpt250 Mt2

Front 1

Direct Mode

Back 1

The explicit operands specify addresses in memory where data values are stored.

Allows for larger values to be delivered since the size of the value is the size of the memory space, but the instructions are longer, as the explicit operands are addresses

Front 2

Register Mode

Back 2

explicit operands specify the CPU register addresses of data. Register mode sinstructions are shorter than direct instructions. because there are less registersthen memory addresses

Front 3

Implied Mode

Back 3

No operands are required, as the instruction syntax implies the operation. This gives very short instructions, but very rigorous instructions

Front 4

Immediate Mode

Back 4

The explicit operands specify the actual values of the operands. This means that there is a trade-off between instruction length and trhe magnitude of the values that ca be used

Front 5

Register Indirect Mode

Back 5

The explicit operand specifies a register in the CPU that has the address of a value in external memory. Then, the length of the instruction is shorter because there are less registers, but you have to load the register with the address of the memory value you want to use.

Front 6

Index Mode

Back 6

Same as Register Indirect Mode, but you add a value to the value obtained in the CPU register, offsetting that value.

Front 7

Relative Mode

Back 7

explicit operand specifies a value that is used to compute the location of the next instruction to be fetched from memory. (This is how branching instructions are implemented)