Clash.Explicit.Moore

Whereas the output of a Mealy machine depends on current transition, the output of a Moore machine depends on the previous state.

Moore machines are strictly less expressive, but may impose laxer timing requirements.

Moore machines with explicit clock and reset ports

moore

Arguments

:: (KnownDomain dom, NFDataX s)

=> Clock dom

Clock to synchronize to

-> Reset dom

-> Enable dom

-> (s -> i -> s)

Transfer function in moore machine form: state -> input -> newstate

-> (s -> o)

Output function in moore machine form: state -> output

-> s

Initial state

-> Signal dom i -> Signal dom o

Synchronous sequential function with input and output matching that of the moore machine

Create a synchronous function from a combinational function describing a moore machine

macT
  :: Int        -- Current state
  -> (Int,Int)  -- Input
  -> (Int,Int)  -- Updated state
macT s (x,y) = x * y + s

mac
  :: KnownDomain dom
  => Clock dom
  -> Reset dom
  -> Enable dom
  -> Signal dom (Int, Int)
  -> Signal dom Int
mac clk rst en = moore clk rst en macT id 0

>>> simulate (mac systemClockGen systemResetGen enableGen) [(0,0),(1,1),(2,2),(3,3),(4,4)]
[0,0,1,5,14...
...

Synchronous sequential functions can be composed just like their combinational counterpart:

dualMac
  :: KnownDomain dom
  => Clock dom
  -> Reset dom
  -> Enable dom
  -> (Signal dom Int, Signal dom Int)
  -> (Signal dom Int, Signal dom Int)
  -> Signal dom Int
dualMac clk rst en (a,b) (x,y) = s1 + s2
  where
    s1 = moore clk rst en mac id 0 (bundle (a,x))
    s2 = moore clk rst en mac id 0 (bundle (b,y))

mooreB

Arguments

:: (KnownDomain dom, NFDataX s, Bundle i, Bundle o)

=> Clock dom

-> Reset dom

-> Enable dom

-> (s -> i -> s)

Transfer function in moore machine form: state -> input -> newstate

-> (s -> o)

Output function in moore machine form: state -> output

-> s

Initial state

-> Unbundled dom i -> Unbundled dom o

Synchronous sequential function with input and output matching that of the moore machine

A version of moore that does automatic Bundleing

Given a functions t and o of types:

t :: Int -> (Bool, Int) -> Int
o :: Int -> (Int, Bool)

When we want to make compositions of t and o in g using moore, we have to write:

g clk rst en a b c = (b1,b2,i2)
  where
    (i1,b1) = unbundle (moore clk rst en t o 0 (bundle (a,b)))
    (i2,b2) = unbundle (moore clk rst en t o 3 (bundle (c,i1)))

Using mooreB however we can write:

g clk rst en a b c = (b1,b2,i2)
  where
    (i1,b1) = mooreB clk rst en t o 0 (a,b)
    (i2,b2) = mooreB clk rst en t o 3 (c,i1)

medvedev :: (KnownDomain dom, NFDataX s) => Clock dom -> Reset dom -> Enable dom -> (s -> i -> s) -> s -> Signal dom i -> Signal dom s

Create a synchronous function from a combinational function describing a moore machine without any output logic

medvedevB :: (KnownDomain dom, NFDataX s, Bundle i, Bundle s) => Clock dom -> Reset dom -> Enable dom -> (s -> i -> s) -> s -> Unbundled dom i -> Unbundled dom s

A version of medvedev that does automatic Bundleing