49 lines
2.5 KiB
Python
49 lines
2.5 KiB
Python
from .insn_rv32i_i_type import *
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"""
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RV32I I-Type Instruction (Load Variation)
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"""
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class InsnRV32IITypeLoad(InsnRV32IIType):
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def __init__(self, params, funct3, mask_shift, is_signed):
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super().__init__(params)
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self.funct3 = funct3
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self.mask_shift = mask_shift
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self.is_signed = is_signed
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self.addr = Signal(self.params.xlen)
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self.result = Signal(8 * self.mask_shift)
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def elaborate(self, platform):
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m = super().elaborate(platform)
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if self.params.csr_misa:
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m.d.comb += self.misa_ok.eq((self.rvfi_csr_misa_rdata & 0) == 0)
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m.d.comb += self.spec_csr_misa_rmask.eq(0)
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else:
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m.d.comb += self.misa_ok.eq(1)
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if self.params.aligned_mem:
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m.d.comb += self.addr.eq(self.rvfi_rs1_rdata + self.insn_imm)
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m.d.comb += self.result.eq(self.rvfi_mem_rdata >> (8 * (self.addr - self.spec_mem_addr)))
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m.d.comb += self.spec_valid.eq(self.rvfi_valid & (~self.insn_padding) & (self.insn_funct3 == self.funct3) & (self.insn_opcode == 0b0000011))
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m.d.comb += self.spec_rs1_addr.eq(self.insn_rs1)
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m.d.comb += self.spec_rd_addr.eq(self.insn_rd)
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m.d.comb += self.spec_mem_addr.eq(self.addr & ~(int(self.params.xlen // 8) - 1))
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m.d.comb += self.spec_mem_rmask.eq(((1 << self.mask_shift) - 1) << (self.addr - self.spec_mem_addr)[:5])
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m.d.comb += self.spec_rd_wdata.eq(Mux(self.spec_rd_addr, Value.as_signed(self.result) if self.is_signed else self.result, 0))
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m.d.comb += self.spec_pc_wdata.eq(self.rvfi_pc_rdata + 4)
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m.d.comb += self.spec_trap.eq(((self.addr & (self.mask_shift - 1)) != 0) | ~self.misa_ok)
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else:
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m.d.comb += self.addr.eq(self.rvfi_rs1_rdata + self.insn_imm)
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m.d.comb += self.result.eq(self.rvfi_mem_rdata)
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m.d.comb += self.spec_valid.eq(self.rvfi_valid & (self.insn_funct3 == self.funct3) & (self.insn_opcode == 0b0000011))
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m.d.comb += self.spec_rs1_addr.eq(self.insn_rs1)
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m.d.comb += self.spec_rd_addr.eq(self.insn_rd)
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m.d.comb += self.spec_mem_addr.eq(self.addr)
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m.d.comb += self.spec_mem_rmask.eq((1 << self.mask_shift) - 1)
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m.d.comb += self.spec_rd_wdata.eq(Mux(self.spec_rd_addr, Value.as_signed(self.result) if self.is_signed else self.result, 0))
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m.d.comb += self.spec_pc_wdata.eq(self.rvfi_pc_rdata + 4)
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m.d.comb += self.spec_trap.eq(~self.misa_ok)
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return m
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