riscv-formal-nmigen/insns/InsnJalr.py

35 lines
1.5 KiB
Python

from InsnRV32IIType import *
"""
JALR instruction
"""
class InsnJalr(InsnRV32IIType):
def __init__(self, RISCV_FORMAL_ILEN, RISCV_FORMAL_XLEN, RISCV_FORMAL_CSR_MISA, RISCV_FORMAL_COMPRESSED):
super().__init__(RISCV_FORMAL_ILEN, RISCV_FORMAL_XLEN, RISCV_FORMAL_CSR_MISA)
self.RISCV_FORMAL_COMPRESSED = RISCV_FORMAL_COMPRESSED
def elaborate(self, platform):
m = super().elaborate(platform)
if self.RISCV_FORMAL_CSR_MISA:
m.d.comb += self.misa_ok.eq((self.rvfi_csr_misa_rdata & 0) == 0)
m.d.comb += self.spec_csr_misa_rmask.eq(4)
m.d.comb += self.ialign16.eq((self.rvfi_csr_misa_rdata & 4) != 0)
else:
m.d.comb += self.misa_ok.eq(1)
if self.RISCV_FORMAL_COMPRESSED:
m.d.comb += self.ialign16.eq(1)
else:
m.d.comb += self.ialign16.eq(0)
next_pc = Signal(self.RISCV_FORMAL_XLEN)
m.d.comb += next_pc.eq((self.rvfi_rs1_rdata + self.insn_imm) & ~1)
m.d.comb += self.spec_valid.eq(self.rvfi_valid & (~self.insn_padding) & (self.insn_funct3 == 0b000) & (self.insn_opcode == 0b1100111))
m.d.comb += self.spec_rs1_addr.eq(self.insn_rs1)
m.d.comb += self.spec_rd_addr.eq(self.insn_rd)
m.d.comb += self.spec_rd_wdata.eq(Mux(self.spec_rd_addr, self.rvfi_pc_rdata + 4, 0))
m.d.comb += self.spec_pc_wdata.eq(next_pc)
m.d.comb += self.spec_trap.eq(Mux(self.ialign16, next_pc[0] != 0, next_pc[:2] != 0) | ~self.misa_ok)
return m