amomin.b

Atomic MIN byte

Atomically:

  • Load the byte at address xs1

  • Write the sign-extended value into xd

  • Signed compare the least-significant byte of register xs2 to the loaded value, and select the minimum value

  • Write the minimum to the address in xs1

Assembly format

amomin.b xd, xs2, (xs1)

Decode Variables

Bits<5> xs2 = $encoding[24:20];
Bits<5> xs1 = $encoding[19:15];
Bits<5> xd = $encoding[11:7];

Execution

if (implemented?(ExtensionName::A) && MISA_CSR_IMPLEMENTED && CSR[misa].A == 1'b0) {
  reserved_instruction($encoding);
}
XReg virtual_address = X[xs1];
X[xd] = amo(8, virtual_address, X[xs2][7:0], AmoOperation::Min, 1'b0, 1'b0, $encoding);

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction

  • LoadAccessFault

  • StoreAmoAccessFault

  • StoreAmoPageFault

Encoding

svg

Defining extension

Zabha

Access

M

Always

Containing profiles

  • Mandatory: None

  • Optional: RVA23U64, RVB23U64