wishbone_dma: convert to new endpoint API and fix some bugs

This commit is contained in:
Sebastien Bourdeauducq 2012-01-15 16:41:15 +01:00
parent 77b3c8e3bb
commit 85491efc68
2 changed files with 40 additions and 11 deletions

20
examples/dataflow_dma.py Normal file
View File

@ -0,0 +1,20 @@
import sys
import networkx as nx
from migen.fhdl import verilog
from migen.flow.ala import *
from migen.flow.network import *
from migen.actorlib import dma_wishbone
L = [
("x", BV(10), 8),
("y", BV(10), 8),
("level2", [
("a", BV(5), 32),
("b", BV(5), 16)
])
]
reader = dma_wishbone.Reader(L)
frag = reader.get_fragment()
print(verilog.convert(frag, ios=set(reader.bus.signals())))

View File

@ -6,36 +6,45 @@ from migen.flow.actor import *
class Reader(Actor):
def __init__(self, layout):
self.address = Record([("a", BV(30))])
self.data = Record(layout)
self.bus = wishbone.Master()
Actor.__init__(self,
SchedulingModel(SchedulingModel.DYNAMIC),
self.address, self.data)
("address", Sink, [("a", BV(30))]),
("data", Source, layout))
def get_fragment(self):
components, length = self.data.flatten(align=True, return_offset=True)
components, length = self.token("data").flatten(align=True, return_offset=True)
nwords = (length + 31)//32
# Address generator
ag_stb = Signal()
ag_sync = [If(ag_stb, self.bus.adr_o.eq(self.address.a))]
ag_sync = [If(ag_stb, self.bus.adr_o.eq(self.token("address").a))]
if nwords > 1:
ag_inc = Signal()
sync.append(If(ag_inc, self.bus.adr_o.eq(self.bus.adr_o + 1)))
ag_sync.append(If(ag_inc, self.bus.adr_o.eq(self.bus.adr_o + 1)))
address_generator = Fragment(sync=ag_sync)
# Output buffer
ob_reg = Signal(BV(length))
ob_stbs = Signal(BV(nwords))
ob_sync = [If(ob_stbs[w], ob_reg[32*w:32*(w+1)].eq(self.bus.dat_i))
for w in range(nwords)]
ob_sync = []
top = length
for w in range(nwords):
if top >= 32:
width = 32
sl = self.bus.dat_i
else:
width = top
sl = self.bus.dat_i[32-top:]
ob_sync.append(If(ob_stbs[w],
ob_reg[top-width:top].eq(sl)))
top -= width
ob_comb = []
offset = 0
for s in components:
w = s.bv.width
if isinstance(s, Signal):
comb.append(s.eq(ob_reg[length-offset-w:length-offset]))
ob_comb.append(s.eq(ob_reg[length-offset-w:length-offset]))
offset += w
output_buffer = Fragment(ob_comb, ob_sync)
@ -55,12 +64,12 @@ class Reader(Actor):
if w == nwords - 1:
next_state = fsm.STROBE
else:
state = getattr(fsm, fetch_states[w+1])
next_state = getattr(fsm, fetch_states[w+1])
fsm.act(state,
self.bus.cyc_o.eq(1),
self.bus.stb_o.eq(1),
ob_stbs[w].eq(1),
If(self.bus.ack_i,
ob_stbs[nwords-w-1].eq(1),
fsm.next_state(next_state)
)
)