225 lines
7.1 KiB
Python
225 lines
7.1 KiB
Python
from migen.fhdl.std import *
|
|
from migen.genlib.misc import optree
|
|
|
|
control_tokens = [0b1101010100, 0b0010101011, 0b0101010100, 0b1010101011]
|
|
|
|
|
|
class Encoder(Module):
|
|
def __init__(self):
|
|
self.d = Signal(8)
|
|
self.c = Signal(2)
|
|
self.de = Signal()
|
|
|
|
self.out = Signal(10)
|
|
|
|
###
|
|
|
|
# stage 1 - count number of 1s in data
|
|
d = Signal(8)
|
|
n1d = Signal(max=9)
|
|
self.sync += [
|
|
n1d.eq(optree("+", [self.d[i] for i in range(8)])),
|
|
d.eq(self.d)
|
|
]
|
|
|
|
# stage 2 - add 9th bit
|
|
q_m = Signal(9)
|
|
q_m8_n = Signal()
|
|
self.comb += q_m8_n.eq((n1d > 4) | ((n1d == 4) & ~d[0]))
|
|
for i in range(8):
|
|
if i:
|
|
curval = curval ^ d[i] ^ q_m8_n
|
|
else:
|
|
curval = d[0]
|
|
self.sync += q_m[i].eq(curval)
|
|
self.sync += q_m[8].eq(~q_m8_n)
|
|
|
|
# stage 3 - count number of 1s and 0s in q_m[:8]
|
|
q_m_r = Signal(9)
|
|
n0q_m = Signal(max=9)
|
|
n1q_m = Signal(max=9)
|
|
self.sync += [
|
|
n0q_m.eq(optree("+", [~q_m[i] for i in range(8)])),
|
|
n1q_m.eq(optree("+", [q_m[i] for i in range(8)])),
|
|
q_m_r.eq(q_m)
|
|
]
|
|
|
|
# stage 4 - final encoding
|
|
cnt = Signal((6, True))
|
|
|
|
s_c = self.c
|
|
s_de = self.de
|
|
for p in range(3):
|
|
new_c = Signal(2)
|
|
new_de = Signal()
|
|
self.sync += new_c.eq(s_c), new_de.eq(s_de)
|
|
s_c, s_de = new_c, new_de
|
|
|
|
self.sync += If(s_de,
|
|
If((cnt == 0) | (n1q_m == n0q_m),
|
|
self.out[9].eq(~q_m_r[8]),
|
|
self.out[8].eq(q_m_r[8]),
|
|
If(q_m_r[8],
|
|
self.out[:8].eq(q_m_r[:8]),
|
|
cnt.eq(cnt + n1q_m - n0q_m)
|
|
).Else(
|
|
self.out[:8].eq(~q_m_r[:8]),
|
|
cnt.eq(cnt + n0q_m - n1q_m)
|
|
)
|
|
).Else(
|
|
If((~cnt[5] & (n1q_m > n0q_m)) | (cnt[5] & (n0q_m > n1q_m)),
|
|
self.out[9].eq(1),
|
|
self.out[8].eq(q_m_r[8]),
|
|
self.out[:8].eq(~q_m_r[:8]),
|
|
cnt.eq(cnt + Cat(0, q_m_r[8]) + n0q_m - n1q_m)
|
|
).Else(
|
|
self.out[9].eq(0),
|
|
self.out[8].eq(q_m_r[8]),
|
|
self.out[:8].eq(q_m_r[:8]),
|
|
cnt.eq(cnt - Cat(0, ~q_m_r[8]) + n1q_m - n0q_m)
|
|
)
|
|
)
|
|
).Else(
|
|
self.out.eq(Array(control_tokens)[s_c]),
|
|
cnt.eq(0)
|
|
)
|
|
|
|
|
|
class _EncoderSerializer(Module):
|
|
def __init__(self, serdesstrobe, pad_p, pad_n):
|
|
self.submodules.encoder = RenameClockDomains(Encoder(), "pix")
|
|
self.d, self.c, self.de = self.encoder.d, self.encoder.c, self.encoder.de
|
|
|
|
###
|
|
|
|
# 2X soft serialization
|
|
ed_2x = Signal(5)
|
|
self.sync.pix2x += ed_2x.eq(Mux(ClockSignal("pix"), self.encoder.out[:5], self.encoder.out[5:]))
|
|
|
|
# 5X hard serialization
|
|
cascade_di = Signal()
|
|
cascade_do = Signal()
|
|
cascade_ti = Signal()
|
|
cascade_to = Signal()
|
|
pad_se = Signal()
|
|
self.specials += [
|
|
Instance("OSERDES2",
|
|
p_DATA_WIDTH=5, p_DATA_RATE_OQ="SDR", p_DATA_RATE_OT="SDR",
|
|
p_SERDES_MODE="MASTER", p_OUTPUT_MODE="DIFFERENTIAL",
|
|
|
|
o_OQ=pad_se,
|
|
i_OCE=1, i_IOCE=serdesstrobe, i_RST=0,
|
|
i_CLK0=ClockSignal("pix10x"), i_CLK1=0, i_CLKDIV=ClockSignal("pix2x"),
|
|
i_D1=ed_2x[4], i_D2=0, i_D3=0, i_D4=0,
|
|
i_T1=0, i_T2=0, i_T3=0, i_T4=0,
|
|
i_TRAIN=0, i_TCE=1,
|
|
i_SHIFTIN1=1, i_SHIFTIN2=1,
|
|
i_SHIFTIN3=cascade_do, i_SHIFTIN4=cascade_to,
|
|
o_SHIFTOUT1=cascade_di, o_SHIFTOUT2=cascade_ti),
|
|
Instance("OSERDES2",
|
|
p_DATA_WIDTH=5, p_DATA_RATE_OQ="SDR", p_DATA_RATE_OT="SDR",
|
|
p_SERDES_MODE="SLAVE", p_OUTPUT_MODE="DIFFERENTIAL",
|
|
|
|
i_OCE=1, i_IOCE=serdesstrobe, i_RST=0,
|
|
i_CLK0=ClockSignal("pix10x"), i_CLK1=0, i_CLKDIV=ClockSignal("pix2x"),
|
|
i_D1=ed_2x[0], i_D2=ed_2x[1], i_D3=ed_2x[2], i_D4=ed_2x[3],
|
|
i_T1=0, i_T2=0, i_T3=0, i_T4=0,
|
|
i_TRAIN=0, i_TCE=1,
|
|
i_SHIFTIN1=cascade_di, i_SHIFTIN2=cascade_ti,
|
|
i_SHIFTIN3=1, i_SHIFTIN4=1,
|
|
o_SHIFTOUT3=cascade_do, o_SHIFTOUT4=cascade_to),
|
|
Instance("OBUFDS", i_I=pad_se, o_O=pad_p, o_OB=pad_n)
|
|
]
|
|
|
|
|
|
class PHY(Module):
|
|
def __init__(self, serdesstrobe, pads):
|
|
self.hsync = Signal()
|
|
self.vsync = Signal()
|
|
self.de = Signal()
|
|
self.r = Signal(8)
|
|
self.g = Signal(8)
|
|
self.b = Signal(8)
|
|
|
|
###
|
|
|
|
self.submodules.es0 = _EncoderSerializer(serdesstrobe, pads.data0_p, pads.data0_n)
|
|
self.submodules.es1 = _EncoderSerializer(serdesstrobe, pads.data1_p, pads.data1_n)
|
|
self.submodules.es2 = _EncoderSerializer(serdesstrobe, pads.data2_p, pads.data2_n)
|
|
self.comb += [
|
|
self.es0.d.eq(self.r),
|
|
self.es1.d.eq(self.g),
|
|
self.es2.d.eq(self.b),
|
|
self.es0.c.eq(Cat(self.hsync, self.vsync)),
|
|
self.es1.c.eq(0),
|
|
self.es2.c.eq(0),
|
|
self.es0.de.eq(self.de),
|
|
self.es1.de.eq(self.de),
|
|
self.es2.de.eq(self.de),
|
|
]
|
|
|
|
|
|
class _EncoderTB(Module):
|
|
def __init__(self, inputs):
|
|
self.outs = []
|
|
self._iter_inputs = iter(inputs)
|
|
self._end_cycle = None
|
|
self.submodules.dut = Encoder()
|
|
self.comb += self.dut.de.eq(1)
|
|
|
|
def do_simulation(self, selfp):
|
|
if self._end_cycle is None:
|
|
try:
|
|
nv = next(self._iter_inputs)
|
|
except StopIteration:
|
|
self._end_cycle = selfp.simulator.cycle_counter + 4
|
|
else:
|
|
selfp.dut.d = nv
|
|
if selfp.simulator.cycle_counter == self._end_cycle:
|
|
raise StopSimulation
|
|
if selfp.simulator.cycle_counter > 4:
|
|
self.outs.append(selfp.dut.out)
|
|
|
|
|
|
def _bit(i, n):
|
|
return (i >> n) & 1
|
|
|
|
|
|
def _decode_tmds(b):
|
|
try:
|
|
c = control_tokens.index(b)
|
|
de = False
|
|
except ValueError:
|
|
c = 0
|
|
de = True
|
|
vsync = bool(c & 2)
|
|
hsync = bool(c & 1)
|
|
|
|
value = _bit(b, 0) ^ _bit(b, 9)
|
|
for i in range(1, 8):
|
|
value |= (_bit(b, i) ^ _bit(b, i-1) ^ (~_bit(b, 8) & 1)) << i
|
|
|
|
return de, hsync, vsync, value
|
|
|
|
if __name__ == "__main__":
|
|
from migen.sim.generic import run_simulation
|
|
from random import Random
|
|
|
|
rng = Random(788)
|
|
test_list = [rng.randrange(256) for i in range(500)]
|
|
tb = _EncoderTB(test_list)
|
|
run_simulation(tb)
|
|
|
|
check = [_decode_tmds(out)[3] for out in tb.outs]
|
|
assert(check == test_list)
|
|
|
|
nb0 = 0
|
|
nb1 = 0
|
|
for out in tb.outs:
|
|
for i in range(10):
|
|
if _bit(out, i):
|
|
nb1 += 1
|
|
else:
|
|
nb0 += 1
|
|
print("0/1: {}/{} ({:.2f})".format(nb0, nb1, nb0/nb1))
|