milkymist/framebuffer/__init__.py

   1 from migen.fhdl.structure import *
   2 from migen.flow.actor import *
   3 from migen.flow.network import *
   4 from migen.flow import plumbing
   5 from migen.actorlib import misc, dma_asmi, structuring, sim
   6 from migen.bank.description import *
   7 from migen.bank import csrgen
   8
   9 _hbits = 11
  10 _vbits = 11
  11
  12 _bpp = 32
  13 _bpc = 10
  14 _pixel_layout = [
  15         ("b", BV(_bpc)),
  16         ("g", BV(_bpc)),
  17         ("r", BV(_bpc)),
  18         ("pad", BV(_bpp-3*_bpc))
  19 ]
  20
  21 _bpc_dac = 8
  22 _dac_layout = [
  23         ("hsync", BV(1)),
  24         ("vsync", BV(1)),
  25         ("b", BV(_bpc_dac)),
  26         ("g", BV(_bpc_dac)),
  27         ("r", BV(_bpc_dac))
  28 ]
  29
  30 class _FrameInitiator(Actor):
  31         def __init__(self, asmi_bits, length_bits, alignment_bits):
  32                 self._alignment_bits = alignment_bits
  33
  34                 self._enable = RegisterField("enable")
  35
  36                 self._hres = RegisterField("hres", _hbits, reset=640)
  37                 self._hsync_start = RegisterField("hsync_start", _hbits, reset=656)
  38                 self._hsync_end = RegisterField("hsync_end", _hbits, reset=752)
  39                 self._hscan = RegisterField("hscan", _hbits, reset=799)
  40
  41                 self._vres = RegisterField("vres", _vbits, reset=480)
  42                 self._vsync_start = RegisterField("vsync_start", _vbits, reset=492)
  43                 self._vsync_end = RegisterField("vsync_end", _vbits, reset=494)
  44                 self._vscan = RegisterField("vscan", _vbits, reset=524)
  45
  46                 self._base = RegisterField("base", asmi_bits + self._alignment_bits)
  47                 self._length = RegisterField("length", length_bits + self._alignment_bits, reset=640*480*4)
  48
  49                 layout = [
  50                         ("hres", BV(_hbits)),
  51                         ("hsync_start", BV(_hbits)),
  52                         ("hsync_end", BV(_hbits)),
  53                         ("hscan", BV(_hbits)),
  54                         ("vres", BV(_vbits)),
  55                         ("vsync_start", BV(_vbits)),
  56                         ("vsync_end", BV(_vbits)),
  57                         ("vscan", BV(_vbits)),
  58                         ("base", BV(asmi_bits)),
  59                         ("length", BV(length_bits))
  60                 ]
  61                 super().__init__(("frame", Source, layout))
  62
  63         def get_registers(self):
  64                 return [self._enable,
  65                         self._hres, self._hsync_start, self._hsync_end, self._hscan,
  66                         self._vres, self._vsync_start, self._vsync_end, self._vscan,
  67                         self._base, self._length]
  68
  69         def get_fragment(self):
  70                 # TODO: make address updates atomic
  71                 token = self.token("frame")
  72                 stb = self.endpoints["frame"].stb
  73                 ack = self.endpoints["frame"].ack
  74                 comb = [
  75                         self.busy.eq(stb),
  76                         token.hres.eq(self._hres.field.r),
  77                         token.hsync_start.eq(self._hsync_start.field.r),
  78                         token.hsync_end.eq(self._hsync_end.field.r),
  79                         token.hscan.eq(self._hscan.field.r),
  80                         token.vres.eq(self._vres.field.r),
  81                         token.vsync_start.eq(self._vsync_start.field.r),
  82                         token.vsync_end.eq(self._vsync_end.field.r),
  83                         token.vscan.eq(self._vscan.field.r),
  84                         token.length.eq(self._length.field.r[self._alignment_bits:])
  85                 ]
  86                 sync = [
  87                         If(ack | ~stb,
  88                                 stb.eq(self._enable.field.r),
  89                                 token.base.eq(self._base.field.r[self._alignment_bits:])
  90                         )
  91                 ]
  92                 return Fragment(comb, sync)
  93
  94 class VTG(Actor):
  95         def __init__(self):
  96                 super().__init__(
  97                         ("timing", Sink, [
  98                                 ("hres", BV(_hbits)),
  99                                 ("hsync_start", BV(_hbits)),
 100                                 ("hsync_end", BV(_hbits)),
 101                                 ("hscan", BV(_hbits)),
 102                                 ("vres", BV(_vbits)),
 103                                 ("vsync_start", BV(_vbits)),
 104                                 ("vsync_end", BV(_vbits)),
 105                                 ("vscan", BV(_vbits))]),
 106                         ("pixels", Sink, _pixel_layout),
 107                         ("dac", Source, _dac_layout)
 108                 )
 109
 110         def get_fragment(self):
 111                 hactive = Signal()
 112                 vactive = Signal()
 113                 active = Signal()
 114
 115                 generate_en = Signal()
 116                 hcounter = Signal(BV(_hbits))
 117                 vcounter = Signal(BV(_vbits))
 118
 119                 skip = _bpc - _bpc_dac
 120                 comb = [
 121                         active.eq(hactive & vactive),
 122                         If(active,
 123                                 self.token("dac").r.eq(self.token("pixels").r[skip:]),
 124                                 self.token("dac").g.eq(self.token("pixels").g[skip:]),
 125                                 self.token("dac").b.eq(self.token("pixels").b[skip:])
 126                         ),
 127
 128                         generate_en.eq(self.endpoints["timing"].stb & (~active | self.endpoints["pixels"].stb)),
 129                         self.endpoints["pixels"].ack.eq(self.endpoints["dac"].ack & active),
 130                         self.endpoints["dac"].stb.eq(generate_en)
 131                 ]
 132                 tp = self.token("timing")
 133                 sync = [
 134                         self.endpoints["timing"].ack.eq(0),
 135                         If(generate_en & self.endpoints["dac"].ack,
 136                                 hcounter.eq(hcounter + 1),
 137
 138                                 If(hcounter == 0, hactive.eq(1)),
 139                                 If(hcounter == tp.hres, hactive.eq(0)),
 140                                 If(hcounter == tp.hsync_start, self.token("dac").hsync.eq(1)),
 141                                 If(hcounter == tp.hsync_end, self.token("dac").hsync.eq(0)),
 142                                 If(hcounter == tp.hscan,
 143                                         hcounter.eq(0),
 144                                         If(vcounter == tp.vscan,
 145                                                 vcounter.eq(0),
 146                                                 self.endpoints["timing"].ack.eq(1)
 147                                         ).Else(
 148                                                 vcounter.eq(vcounter + 1)
 149                                         )
 150                                 ),
 151
 152                                 If(vcounter == 0, vactive.eq(1)),
 153                                 If(vcounter == tp.vres, vactive.eq(0)),
 154                                 If(vcounter == tp.vsync_start, self.token("dac").vsync.eq(1)),
 155                                 If(vcounter == tp.vsync_end, self.token("dac").vsync.eq(0))
 156                         )
 157                 ]
 158
 159                 return Fragment(comb, sync)
 160
 161 class FIFO(Actor):
 162         def __init__(self):
 163                 super().__init__(("dac", Sink, _dac_layout))
 164
 165                 self.vga_clk = Signal()
 166                 self.vga_hsync_n = Signal()
 167                 self.vga_vsync_n = Signal()
 168                 self.vga_r = Signal(BV(_bpc_dac))
 169                 self.vga_g = Signal(BV(_bpc_dac))
 170                 self.vga_b = Signal(BV(_bpc_dac))
 171
 172         def get_fragment(self):
 173                 data_width = 2+3*_bpc_dac
 174                 asfifo = Instance("asfifo",
 175                         Instance.Parameter("data_width", data_width),
 176                         Instance.Parameter("address_width", 8),
 177
 178                         Instance.Output("data_out", BV(data_width)),
 179                         Instance.Output("empty", BV(1)),
 180                         Instance.Input("read_en", BV(1)),
 181                         Instance.Input("clk_read", self.vga_clk),
 182
 183                         Instance.Input("data_in", BV(data_width)),
 184                         Instance.Output("full", BV(1)),
 185                         Instance.Input("write_en", BV(1)),
 186                         Instance.ClockPort("clk_write"),
 187
 188                         Instance.Input("rst", BV(1)))
 189                 t = self.token("dac")
 190                 return Fragment(
 191                         [
 192                                 asfifo.get_io("read_en").eq(1),
 193                                 Cat(self.vga_hsync_n, self.vga_vsync_n, self.vga_r, self.vga_g, self.vga_b).eq(asfifo.get_io("data_out")),
 194
 195                                 self.endpoints["dac"].ack.eq(~asfifo.get_io("full")),
 196                                 asfifo.get_io("write_en").eq(self.endpoints["dac"].stb),
 197                                 asfifo.get_io("data_in").eq(Cat(~t.hsync, ~t.vsync, t.r, t.g, t.b)),
 198
 199                                 self.busy.eq(0),
 200                                 asfifo.get_io("rst").eq(0)
 201                         ],
 202                         instances=[asfifo])
 203
 204 def sim_fifo_gen():
 205         while True:
 206                 t = sim.Token("dac")
 207                 yield t
 208                 print("H/V:" + str(t.value["hsync"]) + str(t.value["vsync"])
 209                         + " " + str(t.value["r"]) + " " + str(t.value["g"]) + " " + str(t.value["b"]))
 210
 211
 212 class Framebuffer:
 213         def __init__(self, address, asmiport, simulation=False):
 214                 asmi_bits = asmiport.hub.aw
 215                 alignment_bits = bits_for(asmiport.hub.dw//8) - 1
 216                 length_bits = _hbits + _vbits + 2 - alignment_bits
 217                 pack_factor = asmiport.hub.dw//_bpp
 218                 packed_pixels = structuring.pack_layout(_pixel_layout, pack_factor)
 219
 220                 fi = ActorNode(_FrameInitiator(asmi_bits, length_bits, alignment_bits))
 221                 adrloop = ActorNode(misc.IntSequence(length_bits, asmi_bits))
 222                 adrbuffer = ActorNode(plumbing.Buffer)
 223                 dma = ActorNode(dma_asmi.Reader(asmiport))
 224                 datbuffer = ActorNode(plumbing.Buffer)
 225                 cast = ActorNode(structuring.Cast(asmiport.hub.dw, packed_pixels))
 226                 unpack = ActorNode(structuring.Unpack(pack_factor, _pixel_layout))
 227                 vtg = ActorNode(VTG())
 228                 if simulation:
 229                         fifo = ActorNode(sim.SimActor(sim_fifo_gen(), ("dac", Sink, _dac_layout)))
 230                 else:
 231                         fifo = ActorNode(FIFO())
 232
 233                 g = DataFlowGraph()
 234                 g.add_connection(fi, adrloop, source_subr=["length", "base"])
 235                 g.add_connection(adrloop, adrbuffer)
 236                 g.add_connection(adrbuffer, dma)
 237                 g.add_connection(dma, datbuffer)
 238                 g.add_connection(datbuffer, cast)
 239                 g.add_connection(cast, unpack)
 240                 g.add_connection(unpack, vtg, sink_ep="pixels")
 241                 g.add_connection(fi, vtg, sink_ep="timing", source_subr=[
 242                         "hres", "hsync_start", "hsync_end", "hscan",
 243                         "vres", "vsync_start", "vsync_end", "vscan"])
 244                 g.add_connection(vtg, fifo)
 245                 self._comp_actor = CompositeActor(g, debugger=False)
 246
 247                 self.bank = csrgen.Bank(fi.actor.get_registers() + self._comp_actor.get_registers(),
 248                         address=address)
 249
 250                 # VGA clock input
 251                 if not simulation:
 252                         self.vga_clk = fifo.actor.vga_clk
 253
 254                 # Pads
 255                 self.vga_psave_n = Signal()
 256                 if not simulation:
 257                         self.vga_hsync_n = fifo.actor.vga_hsync_n
 258                         self.vga_vsync_n = fifo.actor.vga_vsync_n
 259                 self.vga_sync_n = Signal()
 260                 self.vga_blank_n = Signal()
 261                 if not simulation:
 262                         self.vga_r = fifo.actor.vga_r
 263                         self.vga_g = fifo.actor.vga_g
 264                         self.vga_b = fifo.actor.vga_b
 265
 266         def get_fragment(self):
 267                 comb = [
 268                         self.vga_sync_n.eq(0),
 269                         self.vga_psave_n.eq(1),
 270                         self.vga_blank_n.eq(1)
 271                 ]
 272                 return self.bank.get_fragment() \
 273                         + self._comp_actor.get_fragment() \
 274                         + Fragment(comb)