Load and store

Fig. 5.9

Instruction provides read and write register numbers, 16-bit offset

Register file provides

Read data 1: base register value to ALU

Read data 2: data value to be stored in data memory

Sign extend provides 32-bit offset value to ALU for addition

ALU generates sum of base and offset as address input to data memory

MemRead, MemWrite controls determine whether to read or write data memory

For load (read), data memory provides data for register write

For store (write), data memory writes data to memory location given by address