From: Sebastien Bourdeauducq Date: Sun, 4 Dec 2011 15:44:38 +0000 (+0100) Subject: Initial import, FHDL basic structure, divider example X-Git-Tag: 24jan2021_ls180~2099^2~1183 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=499b95a519e6f8015871be74cbc19bef0d75c4f2;p=litex.git Initial import, FHDL basic structure, divider example --- 499b95a519e6f8015871be74cbc19bef0d75c4f2 diff --git a/.gitignore b/.gitignore new file mode 100644 index 00000000..8d35cb32 --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +__pycache__ +*.pyc diff --git a/migen/__init__.py b/migen/__init__.py new file mode 100644 index 00000000..e69de29b diff --git a/migen/fhdl/__init__.py b/migen/fhdl/__init__.py new file mode 100644 index 00000000..e69de29b diff --git a/migen/fhdl/structure.py b/migen/fhdl/structure.py new file mode 100644 index 00000000..cdaf48c3 --- /dev/null +++ b/migen/fhdl/structure.py @@ -0,0 +1,207 @@ +import math + +def BitsFor(n): + if n == 0: + return 1 + else: + return int(math.ceil(math.log(n+1, 2))) + +class BV: + def __init__(self, width=1, signed=False): + self.width = width + self.signed = signed + + def __str__(self): + r = str(self.width) + "'" + if self.signed: + r += "s" + r += "d" + return r + +class Value: + def __init__(self, bv): + self.bv = bv + + def __add__(self, other): + return Operator("+", [self, other]) + def __radd__(self, other): + return Operator("+", [other, self]) + def __sub__(self, other): + return Operator("-", [self, other]) + def __rsub__(self, other): + return Operator("-", [other, self]) + def __mul__(self, other): + return Operator("*", [self, other]) + def __rmul__(self, other): + return Operator("*", [other, self]) + def __lshift__(self, other): + return Operator("<<", [self, other]) + def __rlshift__(self, other): + return Operator("<<", [other, self]) + def __rshift__(self, other): + return Operator(">>", [self, other]) + def __rrshift__(self, other): + return Operator(">>", [other, self]) + def __and__(self, other): + return Operator("&", [self, other]) + def __rand__(self, other): + return Operator("&", [other, self]) + def __xor__(self, other): + return Operator("^", [self, other]) + def __rxor__(self, other): + return Operator("^", [other, self]) + def __or__(self, other): + return Operator("|", [self, other]) + def __ror__(self, other): + return Operator("|", [other, self]) + + def __lt__(self, other): + return Operator("<", [self, other]) + def __le__(self, other): + return Operator("<=", [self, other]) + def __eq__(self, other): + return Operator("==", [self, other]) + def __ne__(self, other): + return Operator("!=", [self, other]) + def __gt__(self, other): + return Operator(">", [self, other]) + def __ge__(self, other): + return Operator(">=", [self, other]) + + + def __getitem__(self, key): + if isinstance(key, int): + return Slice(self, key, key+1) + elif isinstance(key, slice): + start = key.start or 0 + stop = key.stop or self.bv.width + if key.step != None: + raise KeyError + return Slice(self, start, stop) + else: + raise KeyError + +class Operator(Value): + def __init__(self, op, operands): + self.op = op + self.operands = list(map(_cst, operands)) + + def __str__(self): + arity = len(self.operands) + if arity == 1: + r = self.op + str(self.operands[0]) + elif arity == 2: + r = str(self.operands[0]) + " " + self.op + " " + str(self.operands[1]) + else: + r = self.op + "(" + ", ".join(map(str, self.operands)) + ")" + return "(" + r + ")" + +class Slice(Value): + def __init__(self, value, start, stop): + self.value = value + self.start = start + self.stop = stop + + def __str__(self): + if self.start + 1 == self.stop: + sr = "[" + str(self.start) + "]" + else: + sr = "[" + str(self.start) + ":" + str(self.stop) + "]" + return str(self.value) + sr + +class Cat(Value): + def __init__(self, *args): + self.l = list(map(_cst, args)) + + def __str__(self): + return "{" + ", ".join(map(str, self.l)) + "}" + +class Constant(Value): + def __init__(self, n, bv=None): + if bv == None: + Value.__init__(self, BV(BitsFor(n))) + else: + Value.__init__(self, bv) + self.n = n + + def __str__(self): + if self.n >= 0: + return str(self.bv) + str(self.n) + else: + return "-" + str(self.bv) + str(-self.n) + +def _cst(x): + if isinstance(x, int): + return Constant(x) + else: + return x + +class Signal(Value): + def __init__(self, bv=BV(), name="anonymous", variable=False, reset=0): + Value.__init__(self, bv) + self.bv = bv + self.variable = variable + self.name = name + self.reset = Constant(reset, bv) + + def __str__(self): + return self.name + +def Declare(parent, name, bv=BV(), variable=False, reset=0): + setattr(parent, name, Signal(bv, parent.__class__.__name__+"_"+name, variable, reset)) + +# statements + +class Assign: + def __init__(self, l, r): + self.l = l + self.r = _cst(r) + + def __str__(self): + return str(self.l) + " = " + str(self.r) + +class StatementList: + def __init__(self, l=[]): + self.l = l + + def __str__(self): + return "\n".join(map(str, self.l)) + +def _sl(x): + if isinstance(x, list): + return StatementList(x) + else: + return x + +def _indent(s): + if s: + return "\t" + s.replace("\n", "\n\t") + else: + return "" + +class If: + def __init__(self, cond, t, f=StatementList()): + self.cond = cond + self.t = _sl(t) + self.f = _sl(f) + + def __str__(self): + r = "if " + str(self.cond) + ":\n" + _indent(str(self.t)) + if self.f.l: + r += "\nelse:\n" + _indent(str(self.f)) + return r + +class Case: + def __init__(self, test, cases=[]): + self.test = test + self.cases = cases + +# + +class Fragment: + def __init__(self, comb=StatementList(), sync=StatementList()): + self.comb = _sl(comb) + self.sync = _sl(sync) + + def __str__(self): + return "Comb:\n" + _indent(str(self.comb)) + "\nSync:\n" + _indent(str(self.sync)) \ No newline at end of file diff --git a/test.py b/test.py new file mode 100644 index 00000000..9a0f1360 --- /dev/null +++ b/test.py @@ -0,0 +1,48 @@ +from migen.fhdl import structure as f +from functools import partial + +class Divider: + def __init__(self, w): + self.w = w + + d = partial(f.Declare, self) + + d("start_i") + d("dividend_i", f.BV(w)) + d("divisor_i", f.BV(w)) + d("ready_o") + d("quotient_o", f.BV(w)) + d("remainder_o", f.BV(w)) + + d("_qr", f.BV(2*w)) + d("_counter", f.BV(f.BitsFor(w))) + d("_divisor_r", f.BV(w)) + d("_diff", f.BV(w+1)) + + def GetFragment(self): + a = f.Assign + comb = [ + a(self.quotient_o, self._qr[:self.w]), + a(self.remainder_o, self._qr[self.w:]), + a(self.ready_o, self._counter == f.Constant(0, self._counter.bv)), + a(self._diff, self.remainder_o - self._divisor_r) + ] + sync = [ + f.If(self.start_i == 1, [ + a(self._counter, self.w), + a(self._qr, self.dividend_i), + a(self._divisor_r, self.divisor_i) + ], [ + f.If(self.ready_o == 0, [ + f.If(self._diff[self.w] == 1, + [a(self._qr, f.Cat(0, self._qr[:2*self.w-1]))], + [a(self._qr, f.Cat(1, self._qr[:self.w-1], self._diff[:self.w]))]), + a(self._counter, self._counter - f.Constant(1, self._counter.bv)), + ]) + ]) + ] + return f.Fragment(comb, sync) + +d = Divider(32) +f = d.GetFragment() +print(f) \ No newline at end of file