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build.{dsl,res,plat}: apply clock constraints to signals, not resources.

Browse source 
This adds the Clock() build DSL element, and adds a resource manager
function add_clock_constraint() that takes a Pin or a Signal.
Note that not all platforms, in particular not any nextpnr platforms
at the moment, can add constraints on arbitrary signals.

Fixes #86.
This commit is contained in:
whitequark 2019-06-05 08:48:36 +00:00
parent ab3f103e5a
commit c9879c795b
7 changed files with 155 additions and 109 deletions
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4
nmigen/build/__init__.py
View file

@ -1,3 +1,3 @@
from .dsl import Pins, DiffPairs, Attrs, Subsignal, Resource, Connector
from .dsl import *
from .res import ResourceError
from .plat import Platform, TemplatedPlatform
from .plat import *

50
nmigen/build/dsl.py
View file

@ -1,7 +1,7 @@
from collections import OrderedDict
__all__ = ["Pins", "DiffPairs", "Attrs", "Subsignal", "Resource", "Connector"]
__all__ = ["Pins", "DiffPairs", "Attrs", "Clock", "Subsignal", "Resource", "Connector"]
class Pins:
@ -83,11 +83,27 @@ class Attrs(OrderedDict):
for k, v in self.items()))
class Clock:
def __init__(self, frequency):
if not isinstance(frequency, (float, int)):
raise TypeError("Clock frequency must be a number")
self.frequency = float(frequency)
@property
def period(self):
return 1 / self.frequency
def __repr__(self):
return "(clock {})".format(self.frequency)
class Subsignal:
def __init__(self, name, *args):
self.name = name
self.ios = []
self.attrs = Attrs()
self.clock = None
if not args:
raise ValueError("Missing I/O constraints")
@ -108,15 +124,33 @@ class Subsignal:
.format(arg, self.ios[-1]))
elif isinstance(arg, Attrs):
self.attrs.update(arg)
elif isinstance(arg, Clock):
if self.ios and isinstance(self.ios[-1], (Pins, DiffPairs)):
if self.clock is None:
self.clock = arg
else:
raise TypeError("I/O constraint must be one of Pins, DiffPairs, Subsignal, "
"or Attrs, not {!r}"
raise ValueError("Clock constraint can be applied only once")
else:
raise TypeError("Clock constraint can only be applied to Pins or DiffPairs, "
"not {!r}"
.format(self.ios[-1]))
else:
raise TypeError("Constraint must be one of Pins, DiffPairs, Subsignal, Attrs, "
"or Clock, not {!r}"
.format(arg))
def _content_repr(self):
parts = []
for io in self.ios:
parts.append(repr(io))
if self.clock is not None:
parts.append(repr(self.clock))
if self.attrs:
parts.append(repr(self.attrs))
return " ".join(parts)
def __repr__(self):
return "(subsignal {} {} {})".format(self.name,
" ".join(map(repr, self.ios)),
repr(self.attrs))
return "(subsignal {} {})".format(self.name, self._content_repr())
class Resource(Subsignal):
@ -126,9 +160,7 @@ class Resource(Subsignal):
self.number = number
def __repr__(self):
return "(resource {} {} {} {})".format(self.name, self.number,
" ".join(map(repr, self.ios)),
repr(self.attrs))
return "(resource {} {} {})".format(self.name, self.number, self._content_repr())
class Connector:

5
nmigen/build/plat.py
View file

@ -20,10 +20,9 @@ __all__ = ["Platform", "TemplatedPlatform"]
class Platform(ResourceManager, metaclass=ABCMeta):
resources = abstractproperty()
connectors = abstractproperty()
clocks = abstractproperty()
def __init__(self):
super().__init__(self.resources, self.connectors, self.clocks)
super().__init__(self.resources, self.connectors)
self.extra_files = OrderedDict()
@ -267,7 +266,7 @@ class TemplatedPlatform(Platform):
plan = BuildPlan(script="build_{}".format(name))
for filename_tpl, content_tpl in self.file_templates.items():
plan.add_file(render(filename_tpl, origin=filename_tpl),
render(content_tpl, origin=filename_tpl))
render(content_tpl, origin=content_tpl))
for filename, content in self.extra_files.items():
plan.add_file(filename, content)
return plan

75
nmigen/build/res.py
View file

@ -1,6 +1,6 @@
from collections import OrderedDict
from .. import *
from ..hdl.ast import *
from ..hdl.rec import *
from ..lib.io import *
@ -15,24 +15,19 @@ class ResourceError(Exception):
class ResourceManager:
def __init__(self, resources, connectors, clocks):
def __init__(self, resources, connectors):
self.resources = OrderedDict()
self._requested = OrderedDict()
self.connectors = OrderedDict()
self._conn_pins = OrderedDict()
self.clocks = OrderedDict()
# Constraint lists
self._ports = []
self._clocks = SignalDict()
self.add_resources(resources)
self.add_connectors(connectors)
for name_number, frequency in clocks:
if not isinstance(name_number, tuple):
name_number = (name_number, 0)
self.add_clock(*name_number, frequency)
def add_resources(self, resources):
for res in resources:
@ -56,19 +51,6 @@ class ResourceManager:
assert conn_pin not in self._conn_pins
self._conn_pins[conn_pin] = plat_pin
def add_clock(self, name, number, frequency):
resource = self.lookup(name, number)
if isinstance(resource.ios[0], Subsignal):
raise TypeError("Cannot constrain frequency of resource {}#{} because it has "
"subsignals"
.format(resource.name, resource.number, frequency))
if (resource.name, resource.number) in self.clocks:
other = self.clocks[resource.name, resource.number]
raise ResourceError("Resource {}#{} is already constrained to a frequency of "
"{:f} MHz"
.format(resource.name, resource.number, other / 1e6))
self.clocks[resource.name, resource.number] = frequency
def lookup(self, name, number=0):
if (name, number) not in self.resources:
raise ResourceError("Resource {}#{} does not exist"
@ -138,12 +120,15 @@ class ResourceManager:
port = Record([("p", len(phys)),
("n", len(phys))], name=name)
if dir == "-":
self._ports.append((resource, None, port, attrs))
return port
pin = None
else:
pin = Pin(len(phys), dir, xdr, name=name)
self._ports.append((resource, pin, port, attrs))
return pin
if pin is not None and resource.clock is not None:
self.add_clock_constraint(pin, resource.clock.frequency)
return pin if pin is not None else port
else:
assert False # :nocov:
@ -206,19 +191,33 @@ class ResourceManager:
for bit, pin_name in enumerate(pin_names):
yield "{}[{}]".format(port_name, bit), pin_name, attrs
def iter_clock_constraints(self):
for name, number in self.clocks.keys() & self._requested.keys():
resource = self.resources[name, number]
period = self.clocks[name, number]
pin = self._requested[name, number]
if pin.dir == "io":
raise ResourceError("Cannot constrain frequency of resource {}#{} because "
"it has been requested as a tristate buffer"
.format(name, number))
if isinstance(resource.ios[0], Pins):
port_name = "{}__io".format(pin.name)
elif isinstance(resource.ios[0], DiffPairs):
port_name = "{}__p".format(pin.name)
def add_clock_constraint(self, clock, frequency):
if not isinstance(clock, (Signal, Pin)):
raise TypeError("Object {!r} is not a Signal or Pin".format(clock))
if not isinstance(frequency, (int, float)):
raise TypeError("Frequency must be a number, not {!r}".format(frequency))
if isinstance(clock, Pin):
for res, pin, port, attrs in self._ports:
if clock is pin:
if isinstance(res.ios[0], Pins):
clock = port.io
elif isinstance(res.ios[0], DiffPairs):
clock = port.p
else:
assert False
yield (port_name, period)
break
else:
raise ValueError("Cannot add clock constraint on a Pin {!r} that is not "
"a previously requested resource"
.format(clock))
if clock in self._clocks:
raise ValueError("Cannot add clock constraint on {!r}, which is already constrained "
"to {} Hz"
.format(clock, self._clocks[clock]))
self._clocks[clock] = float(frequency)
def iter_clock_constraints(self):
return iter(self._clocks.items())

38
nmigen/test/test_build_dsl.py
View file

@ -96,6 +96,14 @@ class AttrsTestCase(FHDLTestCase):
a = Attrs(FOO=1)
class ClockTestCase(FHDLTestCase):
def test_basic(self):
c = Clock(1_000_000)
self.assertEqual(c.frequency, 1e6)
self.assertEqual(c.period, 1e-6)
self.assertEqual(repr(c), "(clock 1000000.0)")
class SubsignalTestCase(FHDLTestCase):
def test_basic_pins(self):
s = Subsignal("a", Pins("A0"), Attrs(IOSTANDARD="LVCMOS33"))
@ -105,15 +113,15 @@ class SubsignalTestCase(FHDLTestCase):
def test_basic_diffpairs(self):
s = Subsignal("a", DiffPairs("A0", "B0"))
self.assertEqual(repr(s),
"(subsignal a (diffpairs io (p A0) (n B0)) (attrs ))")
"(subsignal a (diffpairs io (p A0) (n B0)))")
def test_basic_subsignals(self):
s = Subsignal("a",
Subsignal("b", Pins("A0")),
Subsignal("c", Pins("A1")))
self.assertEqual(repr(s),
"(subsignal a (subsignal b (pins io A0) (attrs )) "
"(subsignal c (pins io A1) (attrs )) (attrs ))")
"(subsignal a (subsignal b (pins io A0)) "
"(subsignal c (pins io A1)))")
def test_attrs(self):
s = Subsignal("a",
@ -128,13 +136,17 @@ class SubsignalTestCase(FHDLTestCase):
s = Subsignal("a", Pins("A0"), Attrs(SLEW="FAST"), Attrs(PULLUP="1"))
self.assertEqual(s.attrs, {"SLEW": "FAST", "PULLUP": "1"})
def test_clock(self):
s = Subsignal("a", Pins("A0"), Clock(1e6))
self.assertEqual(s.clock.frequency, 1e6)
def test_wrong_empty_io(self):
with self.assertRaises(ValueError, msg="Missing I/O constraints"):
s = Subsignal("a")
def test_wrong_io(self):
with self.assertRaises(TypeError,
msg="I/O constraint must be one of Pins, DiffPairs, Subsignal, or Attrs, "
msg="Constraint must be one of Pins, DiffPairs, Subsignal, Attrs, or Clock, "
"not 'wrong'"):
s = Subsignal("a", "wrong")
@ -153,10 +165,20 @@ class SubsignalTestCase(FHDLTestCase):
def test_wrong_subsignals(self):
with self.assertRaises(TypeError,
msg="Pins and DiffPairs are incompatible with other location or subsignal "
"constraints, but (pins io B0) appears after (subsignal b (pins io A0) "
"(attrs ))"):
"constraints, but (pins io B0) appears after (subsignal b (pins io A0))"):
s = Subsignal("a", Subsignal("b", Pins("A0")), Pins("B0"))
def test_wrong_clock(self):
with self.assertRaises(TypeError,
msg="Clock constraint can only be applied to Pins or DiffPairs, not "
"(subsignal b (pins io A0))"):
s = Subsignal("a", Subsignal("b", Pins("A0")), Clock(1e6))
def test_wrong_clock_many(self):
with self.assertRaises(ValueError,
msg="Clock constraint can be applied only once"):
s = Subsignal("a", Pins("A0"), Clock(1e6), Clock(1e7))
class ResourceTestCase(FHDLTestCase):
def test_basic(self):
@ -165,8 +187,8 @@ class ResourceTestCase(FHDLTestCase):
Subsignal("rx", Pins("A1", dir="i")),
Attrs(IOSTANDARD="LVCMOS33"))
self.assertEqual(repr(r), "(resource serial 0"
" (subsignal tx (pins o A0) (attrs ))"
" (subsignal rx (pins i A1) (attrs ))"
" (subsignal tx (pins o A0))"
" (subsignal rx (pins i A1))"
" (attrs IOSTANDARD=LVCMOS33))")

82
nmigen/test/test_build_res.py
View file

@ -9,8 +9,8 @@ from .tools import *
class ResourceManagerTestCase(FHDLTestCase):
def setUp(self):
self.resources = [
Resource("clk100", 0, DiffPairs("H1", "H2", dir="i")),
Resource("clk50", 0, Pins("K1")),
Resource("clk100", 0, DiffPairs("H1", "H2", dir="i"), Clock(100e6)),
Resource("clk50", 0, Pins("K1"), Clock(50e6)),
Resource("user_led", 0, Pins("A0", dir="o")),
Resource("i2c", 0,
Subsignal("scl", Pins("N10", dir="o")),
@ -20,14 +20,10 @@ class ResourceManagerTestCase(FHDLTestCase):
self.connectors = [
Connector("pmod", 0, "B0 B1 B2 B3 - -"),
]
self.cm = ResourceManager(self.resources, self.connectors, [])
self.cm = ResourceManager(self.resources, self.connectors)
def test_basic(self):
self.clocks = [
("clk100", 100),
(("clk50", 0), 50),
]
self.cm = ResourceManager(self.resources, self.connectors, self.clocks)
self.cm = ResourceManager(self.resources, self.connectors)
self.assertEqual(self.cm.resources, {
("clk100", 0): self.resources[0],
("clk50", 0): self.resources[1],
@ -37,10 +33,6 @@ class ResourceManagerTestCase(FHDLTestCase):
self.assertEqual(self.cm.connectors, {
("pmod", 0): self.connectors[0],
})
self.assertEqual(self.cm.clocks, {
("clk100", 0): 100,
("clk50", 0): 50,
})
def test_add_resources(self):
new_resources = [
@ -152,23 +144,28 @@ class ResourceManagerTestCase(FHDLTestCase):
)
])
spi0 = self.cm.request("spi", 0)
self.assertEqual(list(sorted(self.cm.iter_port_constraints())), [
self.assertEqual(list(self.cm.iter_port_constraints()), [
("spi_0__ss__io", ["B0"], {}),
("spi_0__clk__io", ["B1"], {}),
("spi_0__miso__io", ["B2"], {}),
("spi_0__mosi__io", ["B3"], {}),
("spi_0__ss__io", ["B0"], {}),
])
def test_request_clock(self):
clk100 = self.cm.request("clk100", 0)
clk50 = self.cm.request("clk50", 0, dir="i")
clk100_port_p, clk100_port_n, clk50_port = self.cm.iter_ports()
self.assertEqual(list(self.cm.iter_clock_constraints()), [
(clk100_port_p, 100e6),
(clk50_port, 50e6)
])
def test_add_clock(self):
self.cm.add_clock("clk100", 0, 10e6)
self.assertEqual(self.cm.clocks["clk100", 0], 10e6)
self.cm.add_clock("clk50", 0, 5e6)
clk100 = self.cm.request("clk100", 0)
clk50 = self.cm.request("clk50", 0, dir="i")
self.assertEqual(list(sorted(self.cm.iter_clock_constraints())), [
("clk100_0__p", 10e6),
("clk50_0__io", 5e6)
i2c = self.cm.request("i2c")
self.cm.add_clock_constraint(i2c.scl, 100e3)
scl_port, sda_port = self.cm.iter_ports()
self.assertEqual(list(self.cm.iter_clock_constraints()), [
(scl_port, 100e3)
])
def test_wrong_resources(self):
@ -177,8 +174,8 @@ class ResourceManagerTestCase(FHDLTestCase):
def test_wrong_resources_duplicate(self):
with self.assertRaises(NameError,
msg="Trying to add (resource user_led 0 (pins o A1) (attrs )), but "
"(resource user_led 0 (pins o A0) (attrs )) has the same name and number"):
msg="Trying to add (resource user_led 0 (pins o A1)), but "
"(resource user_led 0 (pins o A0)) has the same name and number"):
self.cm.add_resources([Resource("user_led", 0, Pins("A1", dir="o"))])
def test_wrong_connectors(self):
@ -196,25 +193,15 @@ class ResourceManagerTestCase(FHDLTestCase):
msg="Resource user_led#1 does not exist"):
r = self.cm.lookup("user_led", 1)
def test_wrong_frequency_subsignals(self):
def test_wrong_clock_signal(self):
with self.assertRaises(TypeError,
msg="Cannot constrain frequency of resource i2c#0 because "
"it has subsignals"):
self.cm.add_clock("i2c", 0, 10e6)
msg="Object None is not a Signal or Pin"):
self.cm.add_clock_constraint(None, 10e6)
def test_wrong_frequency_tristate(self):
with self.assertRaises(ResourceError,
msg="Cannot constrain frequency of resource clk50#0 because "
"it has been requested as a tristate buffer"):
self.cm.add_clock("clk50", 0, 20e6)
clk50 = self.cm.request("clk50", 0)
list(self.cm.iter_clock_constraints())
def test_wrong_frequency_duplicate(self):
with self.assertRaises(ResourceError,
msg="Resource clk100#0 is already constrained to a frequency of 10.000000 MHz"):
self.cm.add_clock("clk100", 0, 10e6)
self.cm.add_clock("clk100", 0, 5e6)
def test_wrong_clock_frequency(self):
with self.assertRaises(TypeError,
msg="Frequency must be a number, not None"):
self.cm.add_clock_constraint(Signal(), None)
def test_wrong_request_duplicate(self):
with self.assertRaises(ResourceError,
@ -238,7 +225,7 @@ class ResourceManagerTestCase(FHDLTestCase):
def test_wrong_request_with_dir_dict(self):
with self.assertRaises(TypeError,
msg="Directions must be a dict, not 'i', because (resource i2c 0 (subsignal scl "
"(pins o N10) (attrs )) (subsignal sda (pins io N11) (attrs )) (attrs )) "
"(pins o N10)) (subsignal sda (pins io N11))) "
"has subsignals"):
i2c = self.cm.request("i2c", 0, dir="i")
@ -250,6 +237,13 @@ class ResourceManagerTestCase(FHDLTestCase):
def test_wrong_request_with_xdr_dict(self):
with self.assertRaises(TypeError,
msg="Data rate must be a dict, not 2, because (resource i2c 0 (subsignal scl "
"(pins o N10) (attrs )) (subsignal sda (pins io N11) (attrs )) (attrs )) "
"(pins o N10)) (subsignal sda (pins io N11))) "
"has subsignals"):
i2c = self.cm.request("i2c", 0, xdr=2)
def test_wrong_clock_constraint_twice(self):
clk100 = self.cm.request("clk100")
with self.assertRaises(ValueError,
msg="Cannot add clock constraint on (sig clk100_0__p), which is already "
"constrained to 100000000.0 Hz"):
self.cm.add_clock_constraint(clk100, 1e6)

4
nmigen/vendor/lattice_ice40.py vendored
View file

@ -76,9 +76,9 @@ class LatticeICE40Platform(TemplatedPlatform):
""",
"{{name}}_pre_pack.py": r"""
# {{autogenerated}}
{% for port_name, frequency in platform.iter_clock_constraints() -%}
{% for signal, frequency in platform.iter_clock_constraints() -%}
{# Clock in MHz #}
ctx.addClock("{{port_name}}", {{frequency/1000000}})
ctx.addClock("{{signal.name}}", {{frequency/1000000}})
{% endfor%}
""",
}