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cxp upconn gw: add low speed serial PHY 

testing: add debug fifo output b4 encoder
cxp upconn: add low speed serial
cxp upconn: add reset, tx_busy, tx_enable
cxp upconn: add clockgen module for 20.83Mbps & 41.66Mbps using counters
cxp upconn: add oserdes using CEInserter
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morgan 2024-06-17 13:19:37 +08:00
parent 75d41c3787
commit 989df99c31
1 changed files with 212 additions and 0 deletions
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src/gateware/cxp_upconn.py Normal file
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from math import ceil
from migen import *
from misoc.cores.code_8b10b import SingleEncoder
from misoc.interconnect import stream
from misoc.interconnect.csr import *
from cxp_pipeline import char_layout
@ResetInserter()
class UpConn_ClockGen(Module):
def __init__(self, sys_clk_freq):
self.clk = Signal()
self.clk_10x = Signal() # 20.83MHz 48ns or 41.66MHz 24ns
self.freq2x_enable = Signal()
# # #
period = 1e9/sys_clk_freq
max_count = ceil(48/period)
counter = Signal(max=max_count, reset=max_count-1)
clk_div = Signal(max=10, reset=9)
self.sync += [
self.clk.eq(0),
self.clk_10x.eq(0),
If(counter == 0,
self.clk_10x.eq(1),
If(self.freq2x_enable,
counter.eq(int(max_count/2)-1),
).Else(
counter.eq(counter.reset),
),
).Else(
counter.eq(counter-1),
),
If(counter == 0,
If(clk_div == 0,
self.clk.eq(1),
clk_div.eq(clk_div.reset),
).Else(
clk_div.eq(clk_div-1),
)
)
]
@ResetInserter()
@CEInserter()
class SERDES_10bits(Module):
def __init__(self, pad):
self.oe = Signal()
self.d = Signal(10)
# # #
o = Signal()
tx_bitcount = Signal(max=10)
tx_reg = Signal(10)
# DEBUG:
self.o = Signal()
self.comb += self.o.eq(o)
self.specials += Instance("OBUF", i_I=o, o_O=pad),
self.sync += [
If(self.oe,
# send LSB first
o.eq(tx_reg[0]),
tx_reg.eq(Cat(tx_reg[1:], 0)),
tx_bitcount.eq(tx_bitcount + 1),
If(tx_bitcount == 9,
tx_bitcount.eq(0),
tx_reg.eq(self.d),
),
).Else(
o.eq(0),
tx_bitcount.eq(0),
)
]
class Debug_buffer(Module,AutoCSR):
def __init__(self, layout):
self.sink_stb = Signal()
self.sink_ack = Signal()
self.sink_data = Signal(8)
self.sink_k = Signal()
# # #
self.submodules.buf_out = buf_out = stream.SyncFIFO(layout, 512)
self.sync += [
buf_out.sink.stb.eq(self.sink_stb),
self.sink_ack.eq(buf_out.sink.ack),
buf_out.sink.data.eq(self.sink_data),
buf_out.sink.k.eq(self.sink_k),
]
self.inc = CSR()
self.dout_pak = CSRStatus(8)
self.kout_pak = CSRStatus()
self.dout_valid = CSRStatus()
self.sync += [
# output
buf_out.source.ack.eq(self.inc.re),
self.dout_pak.status.eq(buf_out.source.data),
self.kout_pak.status.eq(buf_out.source.k),
self.dout_valid.status.eq(buf_out.source.stb),
]
class Transmitter(Module, AutoCSR):
def __init__(self, pad, sys_clk_freq, debug_sma, pmod_pads):
self.bitrate2x_enable = Signal()
self.clk_reset = Signal()
self.tx_enable = Signal()
# # #
self.sink = stream.Endpoint(char_layout)
self.submodules.cg = cg = UpConn_ClockGen(sys_clk_freq)
self.submodules.encoder = encoder = SingleEncoder(True)
self.submodules.debug_buf = debug_buf = Debug_buffer(char_layout)
oe = Signal()
self.sync += [
If(self.tx_enable,
self.sink.ack.eq(0),
# DEBUG:
debug_buf.sink_stb.eq(0),
If(cg.clk,
oe.eq(1),
encoder.disp_in.eq(encoder.disp_out),
self.sink.ack.eq(1),
encoder.d.eq(self.sink.data),
encoder.k.eq(self.sink.k),
# DEBUG:
If(debug_buf.sink_ack,
debug_buf.sink_stb.eq(1),
debug_buf.sink_data.eq(self.sink.data),
debug_buf.sink_k.eq(self.sink.k),
)
)
).Else(
# DEBUG:
debug_buf.sink_stb.eq(0),
# no backpressure
self.sink.ack.eq(1),
oe.eq(0),
)
]
self.submodules.serdes = serdes = SERDES_10bits(pad)
self.comb += [
cg.reset.eq(self.clk_reset),
cg.freq2x_enable.eq(self.bitrate2x_enable),
serdes.reset.eq(self.clk_reset),
serdes.ce.eq(cg.clk_10x),
serdes.d.eq(encoder.output),
serdes.oe.eq(oe),
]
# DEBUG: remove pads
self.specials += [
# # debug sma
# Instance("OBUF", i_I=serdes.o, o_O=debug_sma.p_tx),
# Instance("OBUF", i_I=cg.clk_10x, o_O=debug_sma.n_rx),
# # pmod 0-7 pin
# Instance("OBUF", i_I=serdes.o, o_O=pmod_pads[0]),
# Instance("OBUF", i_I=cg.clk_10x, o_O=pmod_pads[1]),
# Instance("OBUF", i_I=~tx_fifos.pe.n, o_O=pmod_pads[2]),
# Instance("OBUF", i_I=prioity_0, o_O=pmod_pads[3]),
# Instance("OBUF", i_I=word_bound, o_O=pmod_pads[4]),
# Instance("OBUF", i_I=debug_buf.buf_out.sink.stb, o_O=pmod_pads[4]),
# Instance("OBUF", i_I=debug_buf.buf_out.sink.ack, o_O=pmod_pads[5]),
# Instance("OBUF", i_I=debug_buf.buf_out.source.stb, o_O=pmod_pads[6]),
# Instance("OBUF", i_I=debug_buf.buf_out.source.ack, o_O=pmod_pads[7]),
# Instance("OBUF", i_I=scheduler.idling, o_O=pmod_pads[5]),
# # Instance("OBUF", i_I=tx_fifos.source_ack[0], o_O=pmod[6]),
# # Instance("OBUF", i_I=tx_fifos.source_ack[2], o_O=pmod[6]),
# # Instance("OBUF", i_I=tx_fifos.source_ack[1], o_O=pmod[7]),
# Instance("OBUF", i_I=p0, o_O=pmod_pads[6]),
# Instance("OBUF", i_I=p3, o_O=pmod_pads[7]),
]
class CXP_UpConn_PHYS(Module, AutoCSR):
def __init__(self, pads, sys_clk_freq, debug_sma, pmod_pads):
self.tx_phys = []
for i, pad in enumerate(pads):
tx = Transmitter(pad, sys_clk_freq, debug_sma, pmod_pads)
self.tx_phys.append(tx)
setattr(self.submodules, "tx"+str(i), tx)