litex/milkymist/framebuffer/__init__.py
2013-05-09 19:23:22 +02:00

52 lines
1.6 KiB
Python

from migen.fhdl.structure import *
from migen.fhdl.module import Module
from migen.flow.network import *
from migen.bank.description import CSRStorage
from migen.actorlib import dma_asmi, structuring, sim, spi
from milkymist.framebuffer.lib import bpp, pixel_layout, dac_layout, FrameInitiator, VTG, FIFO
class Framebuffer(Module):
def __init__(self, pads, asmiport, simulation=False):
pack_factor = asmiport.hub.dw//(2*bpp)
packed_pixels = structuring.pack_layout(pixel_layout, pack_factor)
fi = FrameInitiator()
dma = spi.DMAReadController(dma_asmi.Reader(asmiport), spi.MODE_EXTERNAL, length_reset=640*480*4)
cast = structuring.Cast(asmiport.hub.dw, packed_pixels, reverse_to=True)
unpack = structuring.Unpack(pack_factor, pixel_layout)
vtg = VTG()
if simulation:
fifo = sim.SimActor(sim_fifo_gen(), ("dac", Sink, dac_layout))
else:
fifo = FIFO()
g = DataFlowGraph()
g.add_connection(fi, vtg, sink_ep="timing")
g.add_connection(dma, cast)
g.add_connection(cast, unpack)
g.add_connection(unpack, vtg, sink_ep="pixels")
g.add_connection(vtg, fifo)
self.submodules += CompositeActor(g)
self._enable = CSRStorage()
self.comb += [
fi.trigger.eq(self._enable.storage),
dma.generator.trigger.eq(self._enable.storage),
]
self._fi = fi
self._dma = dma
# Drive pads
if not simulation:
self.comb += [
pads.hsync_n.eq(fifo.vga_hsync_n),
pads.vsync_n.eq(fifo.vga_vsync_n),
pads.r.eq(fifo.vga_r),
pads.g.eq(fifo.vga_g),
pads.b.eq(fifo.vga_b)
]
self.comb += pads.psave_n.eq(1)
def get_csrs(self):
return [self._enable] + self._fi.get_csrs() + self._dma.get_csrs()