litex/migen/fhdl/verilog.py

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from functools import partial
from operator import itemgetter
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from migen.fhdl.structure import *
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from migen.fhdl.structure import _Operator, _Slice, _Assign, _Fragment
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from migen.fhdl.tools import *
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from migen.fhdl.bitcontainer import bits_for, flen
from migen.fhdl.namer import Namespace, build_namespace
from migen.fhdl.conv_output import ConvOutput
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_reserved_keywords = {
"always", "and", "assign", "automatic", "begin", "buf", "bufif0", "bufif1",
"case", "casex", "casez", "cell", "cmos", "config", "deassign", "default",
"defparam", "design", "disable", "edge", "else", "end", "endcase", "endconfig",
"endfunction", "endgenerate", "endmodule", "endprimitive", "endspecify",
"endtable", "endtask", "event", "for", "force", "forever", "fork", "function",
"generate", "genvar", "highz0", "highz1", "if", "ifnone", "incdir", "include",
"initial", "inout", "input", "instance", "integer", "join", "large", "liblist",
"library", "localparam", "macromodule", "medium", "module", "nand", "negedge",
"nmos", "nor", "noshowcancelled", "not", "notif0", "notif1", "or", "output",
"parameter", "pmos", "posedge", "primitive", "pull0", "pull1" "pulldown"
"pullup","pulsestyle_onevent", "pulsestyle_ondetect", "remos", "real",
"realtime", "reg", "release", "repeat", "rnmos", "rpmos", "rtran", "rtranif0",
"rtranif1", "scalared", "showcancelled", "signed", "small", "specify",
"specparam", "strong0", "strong1", "supply0", "supply1", "table", "task",
"time", "tran", "tranif0", "tranif1", "tri", "tri0", "tri1", "triand",
"trior", "trireg", "unsigned", "use", "vectored", "wait", "wand", "weak0",
"weak1", "while", "wire", "wor","xnor","xor"}
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def _printsig(ns, s):
if s.signed:
n = "signed "
else:
n = ""
if flen(s) > 1:
n += "[" + str(flen(s)-1) + ":0] "
n += ns.get_name(s)
return n
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def _printintbool(node):
if isinstance(node, bool):
if node:
return "1'd1", False
else:
return "1'd0", False
elif isinstance(node, int):
nbits = bits_for(node)
if node >= 0:
return str(nbits) + "'d" + str(node), False
else:
return str(nbits) + "'sd" + str(2**nbits + node), True
else:
raise TypeError
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def _printexpr(ns, node):
if isinstance(node, (int, bool)):
return _printintbool(node)
elif isinstance(node, Signal):
return ns.get_name(node), node.signed
elif isinstance(node, _Operator):
arity = len(node.operands)
r1, s1 = _printexpr(ns, node.operands[0])
if arity == 1:
if node.op == "-":
if s1:
r = node.op + r1
else:
r = "-$signed({1'd0, " + r1 + "})"
s = True
else:
r = node.op + r1
s = s1
elif arity == 2:
r2, s2 = _printexpr(ns, node.operands[1])
if node.op not in ["<<<", ">>>"]:
if s2 and not s1:
r1 = "$signed({1'd0, " + r1 + "})"
if s1 and not s2:
r2 = "$signed({1'd0, " + r2 + "})"
r = r1 + " " + node.op + " " + r2
s = s1 or s2
elif arity == 3:
assert node.op == "m"
r2, s2 = _printexpr(ns, node.operands[1])
r3, s3 = _printexpr(ns, node.operands[2])
if s2 and not s3:
r3 = "$signed({1'd0, " + r3 + "})"
if s3 and not s2:
r2 = "$signed({1'd0, " + r2 + "})"
r = r1 + " ? " + r2 + " : " + r3
s = s2 or s3
else:
raise TypeError
return "(" + r + ")", s
elif isinstance(node, _Slice):
# Verilog does not like us slicing non-array signals...
if isinstance(node.value, Signal) \
and flen(node.value) == 1 \
and node.start == 0 and node.stop == 1:
return _printexpr(ns, node.value)
if node.start + 1 == node.stop:
sr = "[" + str(node.start) + "]"
else:
sr = "[" + str(node.stop-1) + ":" + str(node.start) + "]"
r, s = _printexpr(ns, node.value)
return r + sr, s
elif isinstance(node, Cat):
l = [_printexpr(ns, v)[0] for v in reversed(node.l)]
return "{" + ", ".join(l) + "}", False
elif isinstance(node, Replicate):
return "{" + str(node.n) + "{" + _printexpr(ns, node.v)[0] + "}}", False
else:
raise TypeError("Expression of unrecognized type: "+str(type(node)))
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(_AT_BLOCKING, _AT_NONBLOCKING, _AT_SIGNAL) = range(3)
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def _printnode(ns, at, level, node):
if node is None:
return ""
elif isinstance(node, _Assign):
if at == _AT_BLOCKING:
assignment = " = "
elif at == _AT_NONBLOCKING:
assignment = " <= "
elif is_variable(node.l):
assignment = " = "
else:
assignment = " <= "
return "\t"*level + _printexpr(ns, node.l)[0] + assignment + _printexpr(ns, node.r)[0] + ";\n"
elif isinstance(node, (list, tuple)):
return "".join(list(map(partial(_printnode, ns, at, level), node)))
elif isinstance(node, If):
r = "\t"*level + "if (" + _printexpr(ns, node.cond)[0] + ") begin\n"
r += _printnode(ns, at, level + 1, node.t)
if node.f:
r += "\t"*level + "end else begin\n"
r += _printnode(ns, at, level + 1, node.f)
r += "\t"*level + "end\n"
return r
elif isinstance(node, Case):
if node.cases:
r = "\t"*level + "case (" + _printexpr(ns, node.test)[0] + ")\n"
css = sorted([(k, v) for (k, v) in node.cases.items() if k != "default"], key=itemgetter(0))
for choice, statements in css:
r += "\t"*(level + 1) + _printexpr(ns, choice)[0] + ": begin\n"
r += _printnode(ns, at, level + 2, statements)
r += "\t"*(level + 1) + "end\n"
if "default" in node.cases:
r += "\t"*(level + 1) + "default: begin\n"
r += _printnode(ns, at, level + 2, node.cases["default"])
r += "\t"*(level + 1) + "end\n"
r += "\t"*level + "endcase\n"
return r
else:
return ""
else:
raise TypeError("Node of unrecognized type: "+str(type(node)))
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def _list_comb_wires(f):
r = set()
groups = group_by_targets(f.comb)
for g in groups:
if len(g[1]) == 1 and isinstance(g[1][0], _Assign):
r |= g[0]
return r
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def _printheader(f, ios, name, ns,
reg_initialization):
sigs = list_signals(f) | list_special_ios(f, True, True, True)
special_outs = list_special_ios(f, False, True, True)
inouts = list_special_ios(f, False, False, True)
targets = list_targets(f) | special_outs
wires = _list_comb_wires(f) | special_outs
r = "module " + name + "(\n"
firstp = True
for sig in sorted(ios, key=lambda x: x.huid):
if not firstp:
r += ",\n"
firstp = False
if sig in inouts:
r += "\tinout " + _printsig(ns, sig)
elif sig in targets:
if sig in wires:
r += "\toutput " + _printsig(ns, sig)
else:
r += "\toutput reg " + _printsig(ns, sig)
else:
r += "\tinput " + _printsig(ns, sig)
r += "\n);\n\n"
for sig in sorted(sigs - ios, key=lambda x: x.huid):
if sig in wires:
r += "wire " + _printsig(ns, sig) + ";\n"
else:
if reg_initialization:
r += "reg " + _printsig(ns, sig) + " = " + _printexpr(ns, sig.reset)[0] + ";\n"
else:
r += "reg " + _printsig(ns, sig) + ";\n"
r += "\n"
return r
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def _printcomb(f, ns,
display_run,
dummy_signal,
blocking_assign):
r = ""
if f.comb:
if dummy_signal:
# Generate a dummy event to get the simulator
# to run the combinatorial process once at the beginning.
syn_off = "// synthesis translate_off\n"
syn_on = "// synthesis translate_on\n"
dummy_s = Signal(name_override="dummy_s")
r += syn_off
r += "reg " + _printsig(ns, dummy_s) + ";\n"
r += "initial " + ns.get_name(dummy_s) + " <= 1'd0;\n"
r += syn_on
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groups = group_by_targets(f.comb)
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for n, g in enumerate(groups):
if len(g[1]) == 1 and isinstance(g[1][0], _Assign):
r += "assign " + _printnode(ns, _AT_BLOCKING, 0, g[1][0])
else:
if dummy_signal:
dummy_d = Signal(name_override="dummy_d")
r += "\n" + syn_off
r += "reg " + _printsig(ns, dummy_d) + ";\n"
r += syn_on
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r += "always @(*) begin\n"
if display_run:
r += "\t$display(\"Running comb block #" + str(n) + "\");\n"
if blocking_assign:
for t in g[0]:
r += "\t" + ns.get_name(t) + " = " + _printexpr(ns, t.reset)[0] + ";\n"
r += _printnode(ns, _AT_BLOCKING, 1, g[1])
else:
for t in g[0]:
r += "\t" + ns.get_name(t) + " <= " + _printexpr(ns, t.reset)[0] + ";\n"
r += _printnode(ns, _AT_NONBLOCKING, 1, g[1])
if dummy_signal:
r += syn_off
r += "\t" + ns.get_name(dummy_d) + " <= " + ns.get_name(dummy_s) + ";\n"
r += syn_on
r += "end\n"
r += "\n"
return r
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def _printsync(f, ns):
r = ""
for k, v in sorted(f.sync.items(), key=itemgetter(0)):
r += "always @(posedge " + ns.get_name(f.clock_domains[k].clk) + ") begin\n"
r += _printnode(ns, _AT_SIGNAL, 1, v)
r += "end\n\n"
return r
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def _call_special_classmethod(overrides, obj, method, *args, **kwargs):
cl = obj.__class__
if cl in overrides:
cl = overrides[cl]
if hasattr(cl, method):
return getattr(cl, method)(obj, *args, **kwargs)
else:
return None
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def _lower_specials_step(overrides, specials):
f = _Fragment()
lowered_specials = set()
for special in sorted(specials, key=lambda x: x.huid):
impl = _call_special_classmethod(overrides, special, "lower")
if impl is not None:
f += impl.get_fragment()
lowered_specials.add(special)
return f, lowered_specials
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def _can_lower(overrides, specials):
for special in specials:
cl = special.__class__
if cl in overrides:
cl = overrides[cl]
if hasattr(cl, "lower"):
return True
return False
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def _lower_specials(overrides, specials):
f, lowered_specials = _lower_specials_step(overrides, specials)
while _can_lower(overrides, f.specials):
f2, lowered_specials2 = _lower_specials_step(overrides, f.specials)
f += f2
lowered_specials |= lowered_specials2
f.specials -= lowered_specials2
return f, lowered_specials
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def _printspecials(overrides, specials, ns, add_data_file):
r = ""
for special in sorted(specials, key=lambda x: x.huid):
pr = _call_special_classmethod(overrides, special, "emit_verilog", ns, add_data_file)
if pr is None:
raise NotImplementedError("Special " + str(special) + " failed to implement emit_verilog")
r += pr
return r
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def convert(f, ios=None, name="top",
special_overrides=dict(),
create_clock_domains=True,
display_run=False, asic_syntax=False):
r = ConvOutput()
if not isinstance(f, _Fragment):
f = f.get_fragment()
if ios is None:
ios = set()
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for cd_name in list_clock_domains(f):
try:
f.clock_domains[cd_name]
except KeyError:
if create_clock_domains:
cd = ClockDomain(cd_name)
f.clock_domains.append(cd)
ios |= {cd.clk, cd.rst}
else:
raise KeyError("Unresolved clock domain: '"+cd_name+"'")
f = lower_complex_slices(f)
insert_resets(f)
f = lower_basics(f)
fs, lowered_specials = _lower_specials(special_overrides, f.specials)
f += lower_basics(fs)
ns = build_namespace(list_signals(f) \
| list_special_ios(f, True, True, True) \
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| ios, _reserved_keywords)
r.ns = ns
src = "/* Machine-generated using Migen */\n"
src += _printheader(f, ios, name, ns,
reg_initialization=not asic_syntax)
src += _printcomb(f, ns,
display_run=display_run,
dummy_signal=not asic_syntax,
blocking_assign=asic_syntax)
src += _printsync(f, ns)
src += _printspecials(special_overrides, f.specials - lowered_specials, ns, r.add_data_file)
src += "endmodule\n"
r.set_main_source(src)
return r