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ECP5: Replicate OE signal for each output bit.
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nextpnr can only pack OE FFs into IOLOGIC when there's one OFS1P3DX per
output, rather than one shared instance.
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@adamgreig
adamgreig committed Jan 14, 2021
1 parent 3a4b61c commit 6ea992c
Showing 1 changed file with 19 additions and 12 deletions.
31 changes: 19 additions & 12 deletions nmigen/vendor/lattice_ecp5.py
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Original file line number Diff line number Diff line change
Expand Up @@ -387,6 +387,16 @@ def get_oreg(clk, d, q):
o_Q=q[bit]
)

def get_oereg(clk, oe, q):
for bit in range(len(q)):
m.submodules += Instance("OFS1P3DX",
i_SCLK=clk,
i_SP=Const(1),
i_CD=Const(0),
i_D=oe,
o_Q=q[bit]
)

def get_iddr(sclk, d, q0, q1):
for bit in range(len(d)):
m.submodules += Instance("IDDRX1F",
Expand Down Expand Up @@ -508,7 +518,7 @@ def get_oneg(a, invert):
if "o" in pin.dir:
o = Signal(pin.width, name="{}_xdr_o".format(pin.name))
if pin.dir in ("oe", "io"):
t = Signal(1, name="{}_xdr_t".format(pin.name))
t = Signal(pin.width, name="{}_xdr_t".format(pin.name))

if pin.xdr == 0:
if "i" in pin.dir:
Expand All @@ -523,31 +533,28 @@ def get_oneg(a, invert):
if "o" in pin.dir:
get_oreg(pin.o_clk, pin_o, o)
if pin.dir in ("oe", "io"):
get_oreg(pin.o_clk, ~pin.oe, t)
get_oereg(pin.o_clk, ~pin.oe, t)
elif pin.xdr == 2:
if "i" in pin.dir:
get_iddr(pin.i_clk, i, pin_i0, pin_i1)
if "o" in pin.dir:
get_oddr(pin.o_clk, pin_o0, pin_o1, o)
if pin.dir in ("oe", "io"):
# It looks like Diamond will not pack an OREG as a tristate register in a DDR PIO.
# It is not clear what is the recommended set of primitives for this task.
# Similarly, nextpnr will not pack anything as a tristate register in a DDR PIO.
get_oreg(pin.o_clk, ~pin.oe, t)
get_oereg(pin.o_clk, ~pin.oe, t)
elif pin.xdr == 4:
if "i" in pin.dir:
get_iddrx2(pin.i_clk, pin.i_fclk, i, pin_i0, pin_i1, pin_i2, pin_i3)
if "o" in pin.dir:
get_oddrx2(pin.o_clk, pin.o_fclk, pin_o0, pin_o1, pin_o2, pin_o3, o)
if pin.dir in ("oe", "io"):
get_oreg(pin.o_clk, ~pin.oe, t)
get_oereg(pin.o_clk, ~pin.oe, t)
elif pin.xdr == 7:
if "i" in pin.dir:
get_iddr71b(pin.i_clk, pin.i_fclk, i, pin_i0, pin_i1, pin_i2, pin_i3, pin_i4, pin_i5, pin_i6)
if "o" in pin.dir:
get_oddr71b(pin.o_clk, pin.o_fclk, pin_o0, pin_o1, pin_o2, pin_o3, pin_o4, pin_o5, pin_o6, o)
if pin.dir in ("oe", "io"):
get_oreg(pin.o_clk, ~pin.oe, t)
get_oereg(pin.o_clk, ~pin.oe, t)
else:
assert False

Expand Down Expand Up @@ -584,7 +591,7 @@ def get_tristate(self, pin, port, attrs, invert):
i, o, t = self._get_xdr_buffer(m, pin, o_invert=invert)
for bit in range(pin.width):
m.submodules["{}_{}".format(pin.name, bit)] = Instance("OBZ",
i_T=t,
i_T=t[bit],
i_I=o[bit],
o_O=port.io[bit]
)
Expand All @@ -597,7 +604,7 @@ def get_input_output(self, pin, port, attrs, invert):
i, o, t = self._get_xdr_buffer(m, pin, i_invert=invert, o_invert=invert)
for bit in range(pin.width):
m.submodules["{}_{}".format(pin.name, bit)] = Instance("BB",
i_T=t,
i_T=t[bit],
i_I=o[bit],
o_O=i[bit],
io_B=port.io[bit]
Expand Down Expand Up @@ -635,7 +642,7 @@ def get_diff_tristate(self, pin, port, attrs, invert):
i, o, t = self._get_xdr_buffer(m, pin, o_invert=invert)
for bit in range(pin.width):
m.submodules["{}_{}".format(pin.name, bit)] = Instance("OBZ",
i_T=t,
i_T=t[bit],
i_I=o[bit],
o_O=port.p[bit],
)
Expand All @@ -648,7 +655,7 @@ def get_diff_input_output(self, pin, port, attrs, invert):
i, o, t = self._get_xdr_buffer(m, pin, i_invert=invert, o_invert=invert)
for bit in range(pin.width):
m.submodules["{}_{}".format(pin.name, bit)] = Instance("BB",
i_T=t,
i_T=t[bit],
i_I=o[bit],
o_O=i[bit],
io_B=port.p[bit],
Expand Down

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