Puneet Varma (Editor)

ELLA (programming language)

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ELLA is a Hardware description language and support toolset. Developed by the Royal Signals and Radar Establishment during the 1980s and 1990s.

Includes tools to perform:

  • design transformation
  • symbolic simulations
  • formal verification
  • ELLA is a winner of the 1989 Queen's Award for Technological Achievement.

    Sample

    Sample originally from ftp://ftp.dra.hmg.gb/pub/ella - Public release.

    Code for matrix multiplication hardware design verification:

    MAC ZIP = ([INT n]TYPE t: vector1 vector2) -> [n][2]t: [INT k = 1..n](vector1[k], vector2[k]). MAC TRANSPOSE = ([INT n][INT m]TYPE t: matrix) -> [m][n]t: [INT i = 1..m] [INT j = 1..n] matrix[j][i]. MAC INNER_PRODUCT{FN * = [2]TYPE t -> TYPE s, FN + = [2]s -> s} = ([INT n][2]t: vector) -> s: IF n = 1 THEN *vector[1] ELSE *vector[1] + INNER_PRODUCT {*,+} vector[2..n] FI. MAC MATRIX_MULT {FN * = [2]TYPE t->TYPE s, FN + = [2]s->s} = ([INT n][INT m]t: matrix1, [m][INT p]t: matrix2) -> [n][p]s: BEGIN LET transposed_matrix2 = TRANSPOSE matrix2. OUTPUT [INT i = 1..n][INT j = 1..p] INNER_PRODUCT{*,+}ZIP(matrix1[i],transposed_matrix2[j]) END. TYPE element = NEW elt/(1..20), product = NEW prd/(1..1200). FN PLUS = (product: integer1 integer2) -> product: ARITH integer1 + integer2. FN MULT = (element: integer1 integer2) -> product: ARITH integer1 * integer2. FN MULT_234 = ([2][3]element:matrix1, [3][4]element:matrix2) -> [2][4]product: MATRIX_MULT{MULT,PLUS}(matrix1, matrix2). FN TEST = () -> [2][4]product: ( LET m1 = ((elt/2, elt/1, elt/1), (elt/3, elt/6, elt/9)), m2 = ((elt/6, elt/1, elt/3, elt/4), (elt/9, elt/2, elt/8, elt/3), (elt/6, elt/4, elt/1, elt/2)). OUTPUT MULT_234 (m1, m2) ). COM test: just displaysignal MOC

    References

    ELLA (programming language) Wikipedia