Some notes from Clash Haskell

Blinky.hs

module Blinky(topEntity, main) where
import qualified Data.List as List
import Clash.Prelude

counter :: HiddenClockResetEnable dom => Signal dom (Signed 8)
counter = c
    where c = register 0 (c + 1)
    
pulseHighEveryNTicks :: forall n dom. HiddenClockResetEnable dom
  => 1 <= n
  => SNat n
  -> Signal dom (BitVector 1)
pulseHighEveryNTicks SNat =
  let cntr = register (0 :: Index n) $ satSucc SatWrap <$> cntr
  in register 0 $ pack <$> (cntr .==. 0)

blinky :: HiddenClockResetEnable dom => Signal dom (BitVector 8)
blinky = snd <$> blinky_state
    where
        blinky_state = register (0, 0) (update <$> blinky_state)
        -- test_newl = register 0 (Internal.head# slow_pulse)
        update (slow_counter :: Signed    4,
                led          :: BitVector 8)
             = (slow_counter', led')
            where
                slow_counter' = slow_counter + 1
                led' = case slow_counter of
                        0 -> toggle led
                        _ -> led
        slow_pulse :: HiddenClockResetEnable dom => Signal dom (BitVector 1)
        slow_pulse = pulseHighEveryNTicks (SNat @6_000_000)
        toggle led = case led of
                        0 -> 1
                        1 -> 0
                        _ -> led