24 lines
636 B
Haskell
24 lines
636 B
Haskell
{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE NumericUnderscores #-}
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module Fetch(fetchInstruction) where
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import Clash.Prelude
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import Types(Mem, Addr, FullWord)
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import Util(endianSwapWord)
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data Insn = Instruction FullWord
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| Misaligned Addr
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fetchInstruction :: KnownNat n => Mem n -> Addr -> Insn
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fetchInstruction mem addr =
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let
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isWordAligned = addr .&. 3 == 0
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addrWordAligned = addr `shiftR` 2
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insn = mem !! addrWordAligned
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-- TODO : check if instruction is word aligned and create type
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-- to capture if its not.
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in
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case isWordAligned of
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True -> Instruction insn
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False -> Misaligned addr
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