clash-prelude-0.8.1: CAES Language for Synchronous Hardware - Prelude library

Copyright(C) 2013-2015, University of Twente
LicenseBSD2 (see the file LICENSE)
MaintainerChristiaan Baaij <christiaan.baaij@gmail.com>
Safe HaskellUnsafe
LanguageHaskell2010
Extensions
  • DataKinds
  • FlexibleContexts
  • TypeOperators
  • ExplicitNamespaces

CLaSH.Prelude

Contents

Description

CλaSH (pronounced ‘clash’) is a functional hardware description language that borrows both its syntax and semantics from the functional programming language Haskell. The merits of using a functional language to describe hardware comes from the fact that combinational circuits can be directly modeled as mathematical functions and that functional languages lend themselves very well at describing and (de-)composing mathematical functions.

This package provides:

  • Prelude library containing datatypes and functions for circuit design

To use the library:

For now, CLaSH.Prelude is also the best starting point for exploring the library. A preliminary version of a tutorial can be found in CLaSH.Tutorial. Some circuit examples can be found in CLaSH.Examples.

Synopsis

Creating synchronous sequential circuits

mealy Source

Arguments

:: (s -> i -> (s, o))

Transfer function in mealy machine form: state -> input -> (newstate,output)

-> s

Initial state

-> Signal i -> Signal o

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

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

mac :: Int        -- Current state
    -> (Int,Int)  -- Input
    -> (Int,Int)  -- (Updated state, output)
mac s (x,y) = (s',s)
  where
    s' = x * y + s

topEntity :: Signal (Int, Int) -> Signal Int
topEntity = mealy mac 0
>>> simulate topEntity [(1,1),(2,2),(3,3),(4,4)]
[0,1,5,14...

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

dualMac :: (Signal Int, Signal Int)
        -> (Signal Int, Signal Int)
        -> Signal Int
dualMac (a,b) (x,y) = s1 + s2
  where
    s1 = mealy mac 0 (bundle (a,x))
    s2 = mealy mac 0 (bundle (b,y))

mealyB Source

Arguments

:: (Bundle i, Bundle o) 
=> (s -> i -> (s, o))

Transfer function in mealy machine form: state -> input -> (newstate,output)

-> s

Initial state

-> Unbundled i -> Unbundled o

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

A version of mealy that does automatic Bundleing

Given a function f of type:

f :: Int -> (Bool, Int) -> (Int, (Int, Bool))

When we want to make compositions of f in g using mealy, we have to write:

g a b c = (b1,b2,i2)
  where
    (i1,b1) = unbundle (mealy f 0 (bundle (a,b)))
    (i2,b2) = unbundle (mealy f 3 (bundle (i1,c)))

Using mealyB however we can write:

g a b c = (b1,b2,i2)
  where
    (i1,b1) = mealyB f 0 (a,b)
    (i2,b2) = mealyB f 3 (i1,c)

(<^>) Source

Arguments

:: (Bundle i, Bundle o) 
=> (s -> i -> (s, o))

Transfer function in mealy machine form: state -> input -> (newstate,output)

-> s

Initial state

-> Unbundled i -> Unbundled o

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

Infix version of mealyB

moore Source

Arguments

:: (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 i -> Signal 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

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

topEntity :: Signal (Int, Int) -> Signal Int
topEntity = moore mac id 0
>>> simulate topEntity [(1,1),(2,2),(3,3),(4,4)]
[0,1,5,14...

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

dualMac :: (Signal Int, Signal Int)
        -> (Signal Int, Signal Int)
        -> Signal Int
dualMac (a,b) (x,y) = s1 + s2
  where
    s1 = moore mac id 0 (bundle (a,x))
    s2 = moore mac id 0 (bundle (b,y))

mooreB Source

Arguments

:: (Bundle i, Bundle o) 
=> (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 i -> Unbundled 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 a b c = (b1,b2,i2)
  where
    (i1,b1) = unbundle (moore t o 0 (bundle (a,b)))
    (i2,b2) = unbundle (moore t o 3 (bundle (i1,c)))

Using mooreB however we can write:

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

registerB :: Bundle a => a -> Unbundled a -> Unbundled a Source

Create a register function for product-type like signals (e.g. '(Signal a, Signal b)')

rP :: (Signal Int,Signal Int) -> (Signal Int, Signal Int)
rP = registerB (8,8)
>>> simulateB rP [(1,1),(2,2),(3,3)] :: [(Int,Int)]
[(8,8),(1,1),(2,2),(3,3)...

BlockRAM primitives

blockRam Source

Arguments

:: (KnownNat n, KnownNat m) 
=> Vec n a

Initial content of the BRAM, also determines the size, n, of the BRAM.

NB: MUST be a constant.

-> Signal (Unsigned m)

Write address w

-> Signal (Unsigned m)

Read address r

-> Signal Bool

Write enable

-> Signal a

Value to write (at address w)

-> Signal a

Value of the blockRAM at address r from the previous clock cycle

Create a blockRAM with space for n elements.

  • NB: Read value is delayed by 1 cycle
  • NB: Initial output value is undefined
bram40 :: Signal (Unsigned 6) -> Signal (Unsigned 6) -> Signal Bool
       -> Signal Bit -> Signal Bit
bram40 = blockRam (replicate d40 1)

blockRamPow2 Source

Arguments

:: (KnownNat (2 ^ n), KnownNat n) 
=> Vec (2 ^ n) a

Initial content of the BRAM, also determines the size, 2^n, of the BRAM.

NB: MUST be a constant.

-> Signal (Unsigned n)

Write address w

-> Signal (Unsigned n)

Read address r

-> Signal Bool

Write enable

-> Signal a

Value to write (at address w)

-> Signal a

Value of the blockRAM at address r from the previous clock cycle

Create a blockRAM with space for 2^n elements

  • NB: Read value is delayed by 1 cycle
  • NB: Initial output value is undefined
bram32 :: Signal (Unsigned 5) -> Signal (Unsigned 5) -> Signal Bool
       -> Signal Bit -> Signal Bit
bram32 = blockRamPow2 (replicate d32 1)

Utility functions

window Source

Arguments

:: (KnownNat n, Default a) 
=> Signal a

Signal to create a window over

-> Vec (n + 1) (Signal a)

Window of at least size 1

Give a window over a Signal

window4 :: Signal Int -> Vec 4 (Signal Int)
window4 = window
>>> simulateB window4 [1::Int,2,3,4,5] :: [Vec 4 Int]
[<1,0,0,0>,<2,1,0,0>,<3,2,1,0>,<4,3,2,1>,<5,4,3,2>...

windowD Source

Arguments

:: (KnownNat (n + 1), Default a) 
=> Signal a

Signal to create a window over

-> Vec (n + 1) (Signal a)

Window of at least size 1

Give a delayed window over a Signal

windowD3 :: Signal Int -> Vec 3 (Signal Int)
windowD3 = windowD
>>> simulateB windowD3 [1::Int,2,3,4] :: [Vec 3 Int]
[<0,0,0>,<1,0,0>,<2,1,0>,<3,2,1>,<4,3,2>...

isRising Source

Arguments

:: (Bounded a, Eq a) 
=> a

Starting value

-> Signal a 
-> Signal Bool 

Give a pulse when the Signal goes from minBound to maxBound

isFalling Source

Arguments

:: (Bounded a, Eq a) 
=> a

Starting value

-> Signal a 
-> Signal Bool 

Give a pulse when the Signal goes from maxBound to minBound

Testbench functions

assert Source

Arguments

:: (Eq a, Show a) 
=> Signal' t a

Checked value

-> Signal' t a

Expected value

-> Signal' t b

Return valued

-> Signal' t b 

Compares the first two arguments for equality and logs a warning when they are not equal. The second argument is considered the expected value. This function simply returns the third argument unaltered as its result. This function is used by coutputVerifier.

NB: This function is can be used in synthesizable designs.

stimuliGenerator Source

Arguments

:: KnownNat l 
=> Vec l a

Samples to generate

-> Signal a

Signal of given samples

To be used as a one of the functions to create the "magical" testInput value, which the CλaSH compilers looks for to create the stimulus generator for the generated VHDL testbench.

Example:

testInput :: Signal Int
testInput = stimuliGenerator $(v [(1::Int),3..21])
>>> sampleN 13 testInput
[1,3,5,7,9,11,13,15,17,19,21,21,21]

outputVerifier Source

Arguments

:: (KnownNat l, Eq a, Show a) 
=> Vec l a

Samples to compare with

-> Signal a

Signal to verify

-> Signal Bool

Indicator that all samples are verified

To be used as a functions to generate the "magical" expectedOutput function, which the CλaSH compilers looks for to create the signal verifier for the generated VHDL testbench.

Example:

expectedOutput :: Signal Int -> Signal Bool
expectedOutput = outputVerifier $(v ([70,99,2,3,4,5,7,8,9,10]::[Int]))
>>> import qualified Data.List as List
>>> sampleN 12 (expectedOutput (fromList ([0..10] List.++ [10,10,10])))
[
expected value: 70, not equal to actual value: 0
False,
expected value: 99, not equal to actual value: 1
False,False,False,False,False,
expected value: 7, not equal to actual value: 6
False,
expected value: 8, not equal to actual value: 7
False,
expected value: 9, not equal to actual value: 8
False,
expected value: 10, not equal to actual value: 9
False,True,True]

Exported modules

Synchronous signals

DataFlow interface

Datatypes

Bit vectors

Arbitrary-width numbers

Fixed point numbers

Fixed size vectors

Annotations

Type-level natural numbers

Type-level functions

Template Haskell

class Lift t where

Methods

lift :: t -> Q Exp

Instances

Lift Bool 
Lift Char 
Lift Double 
Lift Float 
Lift Int 
Lift Int8 
Lift Int16 
Lift Int32 
Lift Int64 
Lift Integer 
Lift Word 
Lift Word8 
Lift Word16 
Lift Word32 
Lift Word64 
Lift () 
Lift Natural 
Lift a => Lift [a] 
Integral a => Lift (Ratio a) 
Lift a => Lift (Maybe a) 
KnownNat n => Lift (Index n) 
KnownNat n => Lift (BitVector n) 
KnownNat n => Lift (Signed n) 
KnownNat n => Lift (Unsigned n) 
(Lift a, Lift b) => Lift (Either a b) 
(Lift a, Lift b) => Lift (a, b) 
Lift a => Lift (Signal' clk a) 
Lift a => Lift (Vec n a) 
Lift a => Lift (DSignal delay a) 
(Lift a, Lift b, Lift c) => Lift (a, b, c) 
(Lift (rep ((+) int frac)), KnownNat frac, KnownNat int, Typeable (Nat -> *) rep) => Lift (Fixed rep int frac) 
(Lift a, Lift b, Lift c, Lift d) => Lift (a, b, c, d) 
(Lift a, Lift b, Lift c, Lift d, Lift e) => Lift (a, b, c, d, e) 
(Lift a, Lift b, Lift c, Lift d, Lift e, Lift f) => Lift (a, b, c, d, e, f) 
(Lift a, Lift b, Lift c, Lift d, Lift e, Lift f, Lift g) => Lift (a, b, c, d, e, f, g) 

deriveLift :: Name -> Q [Dec]

Derive Lift instances for the given datatype.

Type classes

CLaSH

Other

module Data.Bits

Haskell Prelude

CLaSH.Prelude re-exports most of the Haskell Prelude with the exception of the following: (++), (!!), concat, drop, foldl, foldl1, foldr, foldr1, head, init, iterate, last, length, map, repeat, replicate, reverse, scanl, scanr, splitAt, tail, take, unzip, unzip3, zip, zip3, zipWith, zipWith3.

It instead exports the identically named functions defined in terms of Vec at CLaSH.Sized.Vector.

module Prelude