Star on github

lbu

Load byte unsigned

Loads the byte at the address in the second register plus an offset into the first, zero-extended to the register width.

RISC-V manual: lbu

Used in

Forms

  • lbu , ()

Pseudo-instructions

The processor does not have these forms. The assembler replaces each of them with one or more real instructions. Open a row to see them.

  • Set $t1 to zero-extended 8-bit value from effective memory byte address

  • Load from Address

Operands

t1
Any integer register, x0 to x31, or its named alias, such as zero, t0 or t6.
imm12
A signed 12-bit immediate, -2048 to 2047.
t2
An integer register. It may be the same register as t1.
imm
An immediate value: a signed 12-bit value (-2048 to 2047) or a 32-bit value (-2147483648 to 4294967295). The size your value needs decides which real instructions the assembler uses. Open the row to see them for each size.
label
A named address in the program, such as the start of a loop or a variable in .data. 
# value is initialized and naturally aligned for this operation.
.data
value: .word 0x017fff80
.text
la t0, value
# The first byte is 0x80; lbu writes 128 to t2.
lbu t2, 0(t0)