"Load 32-bit word from memory or I/O peripheral"
Command in Assembler
Operation: rB <- Mem32rA+f(IMM14)
Assembler syntax: ldw rB, byte_offset(rA)
Description: Computes the effective byte address specified by the sum of rA and the instruction's signed 16-bit value. Loads register rB with the memory word located at the effective byte address. The effective byte address must be word aligned. If the byte address is not a multiple of 4, the operation is undefined.
Usage: In processors with a data cache, this instruction may retrieve the desired data from the cache instead of from memory. For more information on data cache, see the 'Cache and Tightly-Coupled Memory' chapter of the 'Nios II Software Developer's Handbook'.
Instruction type: I
Instruction fields: A=Register index of operand rA
B=Register index of operand rB
IMM16=16-bit signed immediate value