-""" Combinatorial Multi-input multiplexer block conforming to Pipeline API
+""" Combinatorial Multi-input and Multi-output multiplexer blocks
+ conforming to Pipeline API
+
+ Multi-input is complex because if any one input is ready, the output
+ can be ready, and the decision comes from a separate module.
+
+ Multi-output is simple (pretty much identical to UnbufferedPipeline),
+ and the selection is just a mux. The only proviso (difference) being:
+ the outputs not being selected have to have their o_ready signals
+ DEASSERTED.
"""
from math import log
from example_buf_pipe import eq, NextControl, PrevControl, ExampleStage
-class PipelineBase:
+class MultiInControlBase:
""" Common functions for Pipeline API
"""
- def __init__(self, stage, in_multi=None, p_len=1):
- """ pass in a "stage" which may be either a static class or a class
- instance, which has four functions (one optional):
- * ispec: returns input signals according to the input specification
- * ispec: returns output signals to the output specification
- * process: takes an input instance and returns processed data
- * setup: performs any module linkage if the stage uses one.
+ def __init__(self, in_multi=None, p_len=1):
+ """ Multi-input Control class. Conforms to same API as ControlBase...
+ mostly. has additional indices to the *multiple* input stages
+
+ * p: contains ready/valid to the previous stages PLURAL
+ * n: contains ready/valid to the next stage
User must also:
- * add i_data member to PrevControl and
- * add o_data member to NextControl
+ * add i_data members to PrevControl and
+ * add o_data member to NextControl
"""
- self.stage = stage
-
# set up input and output IO ACK (prev/next ready/valid)
p = []
for i in range(p_len):
"""
return self.n.connect_to_next(nxt.p[p_idx])
- def connect_in(self, prev, idx=0, prev_idx=None):
+ def _connect_in(self, prev, idx=0, prev_idx=None):
""" helper function to connect stage to an input source. do not
use to connect stage-to-stage!
"""
if prev_idx is None:
- return self.p[idx].connect_in(prev.p)
- return self.p[idx].connect_in(prev.p[prev_idx])
+ return self.p[idx]._connect_in(prev.p)
+ return self.p[idx]._connect_in(prev.p[prev_idx])
- def connect_out(self, nxt):
+ def _connect_out(self, nxt):
""" helper function to connect stage to an output source. do not
use to connect stage-to-stage!
"""
if nxt_idx is None:
- return self.n.connect_out(nxt.n)
- return self.n.connect_out(nxt.n)
+ return self.n._connect_out(nxt.n)
+ return self.n._connect_out(nxt.n)
def set_input(self, i, idx=0):
""" helper function to set the input data
def ports(self):
res = []
for i in range(len(self.p)):
- res += [self.p[i].i_valid, self.p[i].o_ready,
- self.p[i].i_data]# XXX need flattening!]
- res += [self.n.i_ready, self.n.o_valid,
- self.n.o_data] # XXX need flattening!]
+ p = self.p[i]
+ res += [p.i_valid, p.o_ready]
+ if hasattr(p.i_data, "ports"):
+ res += p.i_data.ports()
+ else:
+ rres = p.i_data
+ if not isinstance(rres, Sequence):
+ rres = [rres]
+ res += rres
+ n = self.n
+ res += [n.i_ready, n.o_valid]
+ if hasattr(n.o_data, "ports"):
+ res += n.o_data.ports()
+ else:
+ rres = n.o_data
+ if not isinstance(rres, Sequence):
+ rres = [rres]
+ res += rres
return res
+class MultiOutControlBase:
+ """ Common functions for Pipeline API
+ """
+ def __init__(self, n_len=1, in_multi=None):
+ """ Multi-output Control class. Conforms to same API as ControlBase...
+ mostly. has additional indices to the multiple *output* stages
+ [MultiInControlBase has multiple *input* stages]
+
+ * p: contains ready/valid to the previou stage
+ * n: contains ready/valid to the next stages PLURAL
+
+ User must also:
+ * add i_data member to PrevControl and
+ * add o_data members to NextControl
+ """
+
+ # set up input and output IO ACK (prev/next ready/valid)
+ self.p = PrevControl(in_multi)
+ n = []
+ for i in range(n_len):
+ n.append(NextControl())
+ self.n = Array(n)
-class CombMultiInPipeline(PipelineBase):
+ def connect_to_next(self, nxt, n_idx=0):
+ """ helper function to connect to the next stage data/valid/ready.
+ """
+ return self.n[n_idx].connect_to_next(nxt.p)
+
+ def _connect_in(self, prev, idx=0):
+ """ helper function to connect stage to an input source. do not
+ use to connect stage-to-stage!
+ """
+ return self.n[idx]._connect_in(prev.p)
+
+ def _connect_out(self, nxt, idx=0, nxt_idx=None):
+ """ helper function to connect stage to an output source. do not
+ use to connect stage-to-stage!
+ """
+ if nxt_idx is None:
+ return self.n[idx]._connect_out(nxt.n)
+ return self.n[idx]._connect_out(nxt.n[nxt_idx])
+
+ def set_input(self, i):
+ """ helper function to set the input data
+ """
+ return eq(self.p.i_data, i)
+
+ def ports(self):
+ res = [self.p.i_valid, self.p.o_ready]
+ if hasattr(self.p.i_data, "ports"):
+ res += self.p.i_data.ports()
+ else:
+ res += self.p.i_data
+
+ for i in range(len(self.n)):
+ n = self.n[i]
+ res += [n.i_ready, n.o_valid]
+ if hasattr(n.o_data, "ports"):
+ res += n.o_data.ports()
+ else:
+ res += n.o_data
+ return res
+
+
+class CombMultiOutPipeline(MultiOutControlBase):
+ """ A multi-input Combinatorial block conforming to the Pipeline API
+
+ Attributes:
+ -----------
+ p.i_data : stage input data (non-array). shaped according to ispec
+ n.o_data : stage output data array. shaped according to ospec
+ """
+
+ def __init__(self, stage, n_len, n_mux):
+ MultiOutControlBase.__init__(self, n_len=n_len)
+ self.stage = stage
+ self.n_mux = n_mux
+
+ # set up the input and output data
+ self.p.i_data = stage.ispec() # input type
+ for i in range(n_len):
+ self.n[i].o_data = stage.ospec() # output type
+
+ def elaborate(self, platform):
+ m = Module()
+
+ if hasattr(self.n_mux, "elaborate"): # TODO: identify submodule?
+ m.submodules += self.n_mux
+
+ # need buffer register conforming to *input* spec
+ r_data = self.stage.ispec() # input type
+ if hasattr(self.stage, "setup"):
+ self.stage.setup(m, r_data)
+
+ # multiplexer id taken from n_mux
+ mid = self.n_mux.m_id
+
+ # temporaries
+ p_i_valid = Signal(reset_less=True)
+ pv = Signal(reset_less=True)
+ m.d.comb += p_i_valid.eq(self.p.i_valid_test)
+ m.d.comb += pv.eq(self.p.i_valid & self.p.o_ready)
+
+ # all outputs to next stages first initialised to zero (invalid)
+ # the only output "active" is then selected by the muxid
+ for i in range(len(self.n)):
+ m.d.comb += self.n[i].o_valid.eq(0)
+ data_valid = self.n[mid].o_valid
+ m.d.comb += self.p.o_ready.eq(~data_valid | self.n[mid].i_ready)
+ m.d.comb += data_valid.eq(p_i_valid | \
+ (~self.n[mid].i_ready & data_valid))
+ with m.If(pv):
+ m.d.comb += eq(r_data, self.p.i_data)
+ m.d.comb += eq(self.n[mid].o_data, self.stage.process(r_data))
+
+ return m
+
+
+class CombMultiInPipeline(MultiInControlBase):
""" A multi-input Combinatorial block conforming to the Pipeline API
Attributes:
"""
def __init__(self, stage, p_len, p_mux):
- PipelineBase.__init__(self, stage, p_len=p_len)
+ MultiInControlBase.__init__(self, p_len=p_len)
+ self.stage = stage
self.p_mux = p_mux
# set up the input and output data
n_i_readyn = Array(n_i_readyn)
data_valid = Array(data_valid)
+ nirn = Signal(reset_less=True)
+ m.d.comb += nirn.eq(~self.n.i_ready)
mid = self.p_mux.m_id
for i in range(p_len):
m.d.comb += data_valid[i].eq(0)
m.d.comb += self.p[i].o_ready.eq(0)
m.d.comb += p_i_valid[mid].eq(self.p_mux.active)
m.d.comb += self.p[mid].o_ready.eq(~data_valid[mid] | self.n.i_ready)
- m.d.comb += n_i_readyn[mid].eq(~self.n.i_ready & data_valid[mid])
+ m.d.comb += n_i_readyn[mid].eq(nirn & data_valid[mid])
anyvalid = Signal(i, reset_less=True)
av = []
for i in range(p_len):
return m
+class CombMuxOutPipe(CombMultiOutPipeline):
+ def __init__(self, stage, n_len):
+ # HACK: stage is also the n-way multiplexer
+ CombMultiOutPipeline.__init__(self, stage, n_len=n_len, n_mux=stage)
+
+ # HACK: n-mux is also the stage... so set the muxid equal to input mid
+ stage.m_id = self.p.i_data.mid
+
+
+
class InputPriorityArbiter:
+ """ arbitration module for Input-Mux pipe, baed on PriorityEncoder
+ """
def __init__(self, pipe, num_rows):
self.pipe = pipe
self.num_rows = num_rows
in_ready = []
for i in range(self.num_rows):
p_i_valid = Signal(reset_less=True)
- m.d.comb += p_i_valid.eq(self.pipe.p[i].i_valid_logic())
+ m.d.comb += p_i_valid.eq(self.pipe.p[i].i_valid_test)
in_ready.append(p_i_valid)
m.d.comb += pe.i.eq(Cat(*in_ready)) # array of input "valids"
m.d.comb += self.active.eq(~pe.n) # encoder active (one input valid)
-class ExamplePipeline(CombMultiInPipeline):
+class PriorityCombMuxInPipe(CombMultiInPipeline):
""" an example of how to use the combinatorial pipeline.
"""
- def __init__(self, p_len=2):
+ def __init__(self, stage, p_len=2):
p_mux = InputPriorityArbiter(self, p_len)
- CombMultiInPipeline.__init__(self, ExampleStage, p_len, p_mux)
+ CombMultiInPipeline.__init__(self, stage, p_len, p_mux)
if __name__ == '__main__':
- dut = ExamplePipeline()
+ dut = PriorityCombMuxInPipe(ExampleStage)
vl = rtlil.convert(dut, ports=dut.ports())
with open("test_combpipe.il", "w") as f:
f.write(vl)
projects / ieee754fpu.git / blobdiff