litex/migen/fhdl/verilog.py

162 lines
4.2 KiB
Python

from functools import partial
from migen.fhdl.structure import *
from migen.fhdl.convtools import *
def _printsig(ns, s):
if s.bv.signed:
n = "signed "
else:
n = ""
if s.bv.width > 1:
n += "[" + str(s.bv.width-1) + ":0] "
n += ns.get_name(s)
return n
def _printexpr(ns, node):
if isinstance(node, Constant):
if node.n >= 0:
return str(node.bv) + str(node.n)
else:
return "-" + str(node.bv) + str(-self.n)
elif isinstance(node, Signal):
return ns.get_name(node)
elif isinstance(node, Operator):
arity = len(node.operands)
if arity == 1:
r = node.op + _printexpr(ns, node.operands[0])
elif arity == 2:
r = _printexpr(ns, node.operands[0]) + " " + node.op + " " + _printexpr(ns, node.operands[1])
else:
raise TypeError
return "(" + r + ")"
elif isinstance(node, Slice):
if node.start + 1 == node.stop:
sr = "[" + str(node.start) + "]"
else:
sr = "[" + str(node.stop-1) + ":" + str(node.start) + "]"
return _printexpr(ns, node.value) + sr
elif isinstance(node, Cat):
l = list(map(partial(_printexpr, ns), node.l))
l.reverse()
return "{" + ", ".join(l) + "}"
elif isinstance(node, Replicate):
return "{" + str(node.n) + "{" + _printexpr(ns, node.v) + "}}"
else:
raise TypeError
def _printnode(ns, level, node):
if isinstance(node, Assign):
if is_variable(node.l):
assignment = " = "
else:
assignment = " <= "
return "\t"*level + _printexpr(ns, node.l) + assignment + _printexpr(ns, node.r) + ";\n"
elif isinstance(node, StatementList):
return "".join(list(map(partial(_printnode, ns, level), node.l)))
elif isinstance(node, If):
r = "\t"*level + "if (" + _printexpr(ns, node.cond) + ") begin\n"
r += _printnode(ns, level + 1, node.t)
if node.f.l:
r += "\t"*level + "end else begin\n"
r += _printnode(ns, level + 1, node.f)
r += "\t"*level + "end\n"
return r
elif isinstance(node, Case):
r = "\t"*level + "case (" + _printexpr(ns, node.test) + ")\n"
for case in node.cases:
r += "\t"*(level + 1) + _printexpr(ns, case[0]) + ": begin\n"
r += _printnode(ns, level + 2, case[1])
r += "\t"*(level + 1) + "end\n"
if node.default.l:
r += "\t"*(level + 1) + "default: begin\n"
r += _printnode(ns, level + 2, node.default)
r += "\t"*(level + 1) + "end\n"
r += "\t"*level + "endcase\n"
return r
else:
raise TypeError
def _printinstances(ns, i, clk, rst):
r = ""
for x in i:
r += x.of + " "
if x.parameters:
r += "#(\n"
firstp = True
for p in x.parameters:
if not firstp:
r += ",\n"
firstp = False
r += "\t." + p[0] + "("
if isinstance(p[1], int) or isinstance(p[1], Constant):
r += str(p[1])
elif isinstance(p[1], str):
r += "\"" + p[1] + "\""
else:
raise TypeError
r += ")"
r += "\n) "
r += ns.get_name(x)
if x.parameters: r += " "
r += "(\n"
ports = list(x.ins.items()) + list(x.outs.items())
if x.clkport:
ports.append((x.clkport, clk))
if x.rstport:
ports.append((x.rstport, rst))
firstp = True
for p in ports:
if not firstp:
r += ",\n"
firstp = False
r += "\t." + p[0] + "(" + ns.get_name(p[1]) + ")"
if not firstp:
r += "\n"
r += ");\n\n"
return r
def Convert(f, ios=set(), name="top", clkname="sys_clk", rstname="sys_rst", ns=None):
if ns is None: ns = Namespace()
clks = Signal(name=clkname)
rsts = Signal(name=rstname)
ios |= f.pads
sigs = list_signals(f)
targets = list_targets(f)
instouts = list_inst_outs(f)
r = "/* Machine-generated using Migen */\n"
r += "module " + name + "(\n"
r += "\tinput " + ns.get_name(clks) + ",\n"
r += "\tinput " + ns.get_name(rsts)
for sig in ios:
if sig in targets:
r += ",\n\toutput reg " + _printsig(ns, sig)
elif sig in instouts:
r += ",\n\toutput " + _printsig(ns, sig)
else:
r += ",\n\tinput " + _printsig(ns, sig)
r += "\n);\n\n"
for sig in sigs - ios:
if sig in instouts:
r += "wire " + _printsig(ns, sig) + ";\n"
else:
r += "reg " + _printsig(ns, sig) + ";\n"
r += "\n"
if f.comb.l:
r += "always @(*) begin\n"
r += _printnode(ns, 1, f.comb)
r += "end\n\n"
if f.sync.l:
r += "always @(posedge " + ns.get_name(clks) + ") begin\n"
r += _printnode(ns, 1, insert_reset(rsts, f.sync))
r += "end\n\n"
r += _printinstances(ns, f.instances, clks, rsts)
r += "endmodule\n"
return r