1 """ Example 5: Making use of PyRTL and Introspection. """
3 from nmigen
import Signal
4 from nmigen
.hdl
.rec
import Record
5 from nmigen
import tracer
6 from nmigen
.compat
.fhdl
.bitcontainer
import value_bits_sign
7 from contextlib
import contextmanager
9 from singlepipe
import eq
12 # The following example shows how pyrtl can be used to make some interesting
13 # hardware structures using python introspection. In particular, this example
14 # makes a N-stage pipeline structure. Any specific pipeline is then a derived
15 # class of SimplePipeline where methods with names starting with "stage" are
16 # stages, and new members with names not starting with "_" are to be registered
21 def __init__(self
, pipe
, name
=None):
24 name
= tracer
.get_var_name(default
=None)
28 def like(cls
, pipe
, value
, name
=None, src_loc_at
=0, **kwargs
):
29 name
= name
or tracer
.get_var_name(depth
=2 + src_loc_at
,
32 src_loc_at_1
= 1 + src_loc_at
33 r
= ObjectProxy(pipe
, value
.name
)
34 for a
in value
.ports():
41 for a
in self
.ports():
43 ai
= getattr(i
, aname
)
49 for aname
in dir(self
):
50 a
= getattr(self
, aname
)
51 if isinstance(a
, Signal
) or isinstance(a
, ObjectProxy
) or \
52 isinstance(a
, Record
):
56 def __setattr__(self
, name
, value
):
57 if name
.startswith('_') or name
== 'name':
58 # do not do anything tricky with variables starting with '_'
59 object.__setattr
__(self
, name
, value
)
61 #rname = "%s_%s" % (self.name, name)
63 if isinstance(value
, ObjectProxy
):
64 new_pipereg
= ObjectProxy
.like(self
._pipe
, value
,
65 name
=rname
, reset_less
=True)
67 new_pipereg
= Signal
.like(value
, name
=rname
, reset_less
=True)
69 object.__setattr
__(self
, name
, new_pipereg
)
70 self
._pipe
.sync
+= eq(new_pipereg
, value
)
74 """ Pipeline builder stage with auto generation of pipeline registers.
77 def __init__(self
, name
, m
, prev
=None):
79 self
._stagename
= name
81 self
._prev
_stage
= prev
83 print ("prev", prev
._preg
_map
)
84 if prev
._stagename
in prev
._preg
_map
:
85 m
= prev
._preg
_map
[prev
._stagename
]
86 self
._preg
_map
[prev
._stagename
] = m
87 if '__nextstage__' in prev
._preg
_map
:
88 m
= prev
._preg
_map
['__nextstage__']
89 self
._preg
_map
[self
._stagename
] = m
90 print ("make current", m
)
92 def __getattr__(self
, name
):
94 return self
._preg
_map
[self
._stagename
][name
]
97 'error, no pipeline register "%s" defined for stage %d'
98 % (name
, self
._stagename
))
100 def __setattr__(self
, name
, value
):
101 if name
.startswith('_'):
102 # do not do anything tricky with variables starting with '_'
103 object.__setattr
__(self
, name
, value
)
105 pipereg_id
= self
._stagename
106 rname
= 'pipereg_' + pipereg_id
+ '_' + name
107 #new_pipereg = Signal(value_bits_sign(value), name=rname,
109 if isinstance(value
, ObjectProxy
):
110 new_pipereg
= ObjectProxy
.like(self
._pipe
, value
,
111 name
=rname
, reset_less
= True)
113 new_pipereg
= Signal
.like(value
, name
=rname
, reset_less
= True)
114 next_stage
= '__nextstage__'
115 if next_stage
not in self
._preg
_map
:
116 self
._preg
_map
[next_stage
] = {}
117 self
._preg
_map
[next_stage
][name
] = new_pipereg
118 self
._m
.d
.sync
+= eq(new_pipereg
, value
)
122 def __init__(self
, m
):
126 def Stage(self
, name
, prev
=None):
127 stage
= PipelineStage(name
, self
.m
, prev
)
129 yield stage
, stage
._m
133 class SimplePipeline
:
134 """ Pipeline builder with auto generation of pipeline registers.
137 def __init__(self
, pipe
):
139 self
._pipeline
_register
_map
= {}
140 self
._current
_stage
_num
= 0
144 for method
in dir(self
):
145 if method
.startswith('stage'):
146 stage_list
.append(method
)
147 for stage
in sorted(stage_list
):
148 stage_method
= getattr(self
, stage
)
150 self
._current
_stage
_num
+= 1
152 def __getattr__(self
, name
):
154 return self
._pipeline
_register
_map
[self
._current
_stage
_num
][name
]
156 raise AttributeError(
157 'error, no pipeline register "%s" defined for stage %d'
158 % (name
, self
._current
_stage
_num
))
160 def __setattr__(self
, name
, value
):
161 if name
.startswith('_'):
162 # do not do anything tricky with variables starting with '_'
163 object.__setattr
__(self
, name
, value
)
165 next_stage
= self
._current
_stage
_num
+ 1
166 pipereg_id
= str(self
._current
_stage
_num
) + 'to' + str(next_stage
)
167 rname
= 'pipereg_' + pipereg_id
+ '_' + name
168 #new_pipereg = Signal(value_bits_sign(value), name=rname,
170 if isinstance(value
, ObjectProxy
):
171 new_pipereg
= ObjectProxy
.like(self
._pipe
, value
,
172 name
=rname
, reset_less
= True)
174 new_pipereg
= Signal
.like(value
, name
=rname
, reset_less
= True)
175 if next_stage
not in self
._pipeline
_register
_map
:
176 self
._pipeline
_register
_map
[next_stage
] = {}
177 self
._pipeline
_register
_map
[next_stage
][name
] = new_pipereg
178 self
._pipe
.sync
+= eq(new_pipereg
, value
)