LR.W

Load Reserved Word

LR.W rd, (rs1)

Loads a word from memory and registers a reservation set for the address.

Details

LR.W loads a word from the memory address in rs1 into rd and registers a reservation on that address. The reservation is used by SC.W to implement load-reserved/store-conditional atomics.

Pseudocode Operation

R[rd] = LoadReserved32(M[R[rs1]]);

Example

LR.W x10, (x11)

Encoding

Binary Layout
00010
31:27
aq
26
rl
25
00000
24:20
rs1
19:15
010
14:12
rd
11:7
0101111
6:0
 
Format R-Type (Atomic)
Opcode 0x2F
Extension A

Operands

  • rd
    Destination Register
  • rs1
    Address