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Refactor JAL instruction

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This commit is contained in:
Donald Sebastian Leung 2020-07-30 13:34:52 +08:00
parent a84b6d50b8
commit 7846ba95ac
1 changed files with 9 additions and 71 deletions
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80
insns/insn_jal.py
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@ -1,82 +1,20 @@
from nmigen import *
from insn_UJ_type import *
class rvfi_insn_jal(Elaboratable):
class rvfi_insn_jal(rvfi_insn_UJ_type):
def __init__(self, RISCV_FORMAL_ILEN=32, RISCV_FORMAL_XLEN=32):
self.RISCV_FORMAL_ILEN = RISCV_FORMAL_ILEN
self.RISCV_FORMAL_XLEN = RISCV_FORMAL_XLEN
self.rvfi_valid = Signal(1)
self.rvfi_insn = Signal(self.RISCV_FORMAL_ILEN)
self.rvfi_pc_rdata = Signal(self.RISCV_FORMAL_XLEN)
self.rvfi_rs1_rdata = Signal(self.RISCV_FORMAL_XLEN)
self.rvfi_rs2_rdata = Signal(self.RISCV_FORMAL_XLEN)
self.rvfi_mem_rdata = Signal(self.RISCV_FORMAL_XLEN)
self.spec_valid = Signal(1)
self.spec_trap = Signal(1)
self.spec_rs1_addr = Signal(5)
self.spec_rs2_addr = Signal(5)
self.spec_rd_addr = Signal(5)
self.spec_rd_wdata = Signal(self.RISCV_FORMAL_XLEN)
self.spec_pc_wdata = Signal(self.RISCV_FORMAL_XLEN)
self.spec_mem_addr = Signal(self.RISCV_FORMAL_XLEN)
self.spec_mem_rmask = Signal(int(self.RISCV_FORMAL_XLEN // 8))
self.spec_mem_wmask = Signal(int(self.RISCV_FORMAL_XLEN // 8))
self.spec_mem_wdata = Signal(self.RISCV_FORMAL_XLEN)
super(rvfi_insn_jal, self).__init__(RISCV_FORMAL_ILEN, RISCV_FORMAL_XLEN)
def ports(self):
input_ports = [
self.rvfi_valid,
self.rvfi_insn,
self.rvfi_pc_rdata,
self.rvfi_rs1_rdata,
self.rvfi_rs2_rdata,
self.rvfi_mem_rdata
]
output_ports = [
self.spec_valid,
self.spec_trap,
self.spec_rs1_addr,
self.spec_rs2_addr,
self.spec_rd_addr,
self.spec_rd_wdata,
self.spec_pc_wdata,
self.spec_mem_addr,
self.spec_mem_rmask,
self.spec_mem_wmask,
self.spec_mem_wdata
]
return input_ports + output_ports
return super(rvfi_insn_jal, self).ports()
def elaborate(self, platform):
m = Module()
# UJ-type instruction format
insn_padding = Signal(self.RISCV_FORMAL_ILEN)
m.d.comb += insn_padding.eq(self.rvfi_insn >> 32)
insn_imm = Signal(self.RISCV_FORMAL_XLEN)
m.d.comb += insn_imm.eq(Value.as_signed(Cat(self.rvfi_insn[21:31], self.rvfi_insn[20], self.rvfi_insn[12:20], self.rvfi_insn[31]) << 1))
insn_rd = Signal(5)
m.d.comb += insn_rd.eq(self.rvfi_insn[7:12])
insn_opcode = Signal(7)
m.d.comb += insn_opcode.eq(self.rvfi_insn[:7])
misa_ok = Signal(1)
m.d.comb += misa_ok.eq(1)
ialign16 = Signal(1)
m.d.comb += ialign16.eq(0)
m = super(rvfi_insn_jal, self).elaborate(platform)
# JAL instruction
next_pc = Signal(self.RISCV_FORMAL_XLEN)
m.d.comb += next_pc.eq(self.rvfi_pc_rdata + insn_imm)
m.d.comb += self.spec_valid.eq(self.rvfi_valid & (~insn_padding) & (insn_opcode == 0b1101111))
m.d.comb += self.spec_rd_addr.eq(insn_rd)
m.d.comb += next_pc.eq(self.rvfi_pc_rdata + self.insn_imm)
m.d.comb += self.spec_valid.eq(self.rvfi_valid & (~self.insn_padding) & (self.insn_opcode == 0b1101111))
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(ialign16, next_pc[0] != 0, next_pc[:2] != 0) | ~misa_ok)
# default assignments
m.d.comb += self.spec_rs1_addr.eq(0)
m.d.comb += self.spec_rs2_addr.eq(0)
m.d.comb += self.spec_mem_addr.eq(0)
m.d.comb += self.spec_mem_rmask.eq(0)
m.d.comb += self.spec_mem_wmask.eq(0)
m.d.comb += self.spec_mem_wdata.eq(0)
m.d.comb += self.spec_trap.eq(Mux(self.ialign16, next_pc[0] != 0, next_pc[:2] != 0) | ~self.misa_ok)
return m