forked from Yehowshua/RiscV-Formal
46 lines
1.7 KiB
Haskell
46 lines
1.7 KiB
Haskell
{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-}
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module Bus() where
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import Clash.Prelude
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import Peripherals.Ram(Ram, RamLine)
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import Machine(Peripherals(..))
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import BusTypes(
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BusError(..),
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TransactionSize(..),
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Request(..),
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BusResponse(..),
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BusVal(..),
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ReadResponse(..),
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WriteResponse(..)
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)
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import Types(Addr,
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Byte, HalfWord, FullWord, DoubleWord, QuadWord)
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alignCheck :: Addr -> TransactionSize -> Bool
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alignCheck addr SizeByte = True
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alignCheck addr SizeHalfWord = addr `mod` 2 == 0
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alignCheck addr SizeWord = addr `mod` 4 == 0
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alignCheck addr SizeDoubleWord = addr `mod` 8 == 0
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alignCheck addr SizeQuadWord = addr `mod` 16 == 0
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-- ram shoudl start at 0x80000000
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-- concatWords :: [Ram -> Addr -> RamLine] -> Ram -> Addr -> RamLine
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-- concatWords readers ram baseAddr = foldl (\acc f -> (acc `shiftL` 32) .|. f ram baseAddr) 0 readers
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-- read :: Request -> Peripherals -> ReadResponse
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-- read (Request addr size) peripherals
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-- | not (alignCheck addr size) = ReadError UnAligned
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-- | addr >= numBytesInRam = ReadError UnMapped
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-- | otherwise =
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-- case size of
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-- SizeByte -> BusByte $ fromIntegral $ extractByte (ramRead 0)
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-- SizeHalfWord -> BusHalfWord $ fromIntegral $ (ramRead 0 `shiftL` 8) .|. ramRead 1
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-- SizeWord -> BusWord $ fromIntegral $ concatReads [0..3]
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-- SizeDoubleWord -> BusDoubleWord $ fromIntegral $ concatReads [0..7]
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-- SizeQuadWord -> BusQuadWord $ fromIntegral $ concatReads [0..15]
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-- where
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-- ramRead offset = Peripherals.Ram.read (ram peripherals) (fromIntegral (addr + offset))
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-- concatReads offsets = foldl (\acc o -> (acc `shiftL` 8) .|. ramRead o) 0 offsets
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