lbu

Load byte unsigned

This instruction is defined by:

Encoding

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Synopsis

Load 8 bits of data into register xd from an address formed by adding xs1 to a signed offset. Zero extend the result.

Access

M

HS

U

VS

VU

Always

Always

Always

Always

Always

Decode Variables

Bits<12> imm = $encoding[31:20];
Bits<5> xs1 = $encoding[19:15];
Bits<5> xd = $encoding[11:7];

Execution

  • Pruned, XLEN == 64

  • Original

XReg virtual_address = X[xs1] + $signed(imm);
X[xd] = %%LINK%func;read_memory;read_memory%%<8>(virtual_address, $encoding);
XReg virtual_address = X[xs1] + $signed(imm);
X[xd] = %%LINK%func;read_memory;read_memory%%<8>(virtual_address, $encoding);

Exceptions

This instruction may result in the following synchronous exceptions:

  • LoadAccessFault

  • LoadPageFault