dvisampler: decode before channel sync

milkymist/dvisampler/__init__.py

@@ -6,6 +6,7 @@ from milkymist.dvisampler.edid import EDID
 from milkymist.dvisampler.clocking import Clocking
 from milkymist.dvisampler.datacapture import DataCapture
 from milkymist.dvisampler.charsync import CharSync
+from milkymist.dvisampler.decoding import Decoding
 from milkymist.dvisampler.chansync import ChanSync
 
 class DVISampler(Module, AutoReg):
@@ -36,11 +37,25 @@ class DVISampler(Module, AutoReg):
 			setattr(self.submodules, name + "_charsync", charsync)
 			self.comb += charsync.raw_data.eq(cap.d)
 
+			decoding = Decoding()
+			setattr(self.submodules, name + "_decod", decoding)
+			self.comb += [
+				decoding.valid_i.eq(charsync.synced),
+				decoding.input.eq(charsync.data)
+			]
+
 		self.submodules.chansync = ChanSync()
 		self.comb += [
-			self.chansync.char_synced.eq(self.data0_charsync.synced & \
-			  self.data1_charsync.synced & self.data2_charsync.synced),
-			self.chansync.data_in0.eq(self.data0_charsync.data),
-			self.chansync.data_in1.eq(self.data1_charsync.data),
-			self.chansync.data_in2.eq(self.data2_charsync.data),
+			self.chansync.valid_i.eq(self.data0_decod.valid_o & \
+			  self.data1_decod.valid_o & self.data2_decod.valid_o),
+			self.chansync.data_in0.eq(self.data0_decod.output),
+			self.chansync.data_in1.eq(self.data1_decod.output),
+			self.chansync.data_in2.eq(self.data2_decod.output),
 		]
+
+		de = self.chansync.data_out0.de
+		r = self.chansync.data_out2.d
+		g = self.chansync.data_out1.d
+		b = self.chansync.data_out0.d
+		hsync = self.chansync.data_out0.c[0]
+		vsync = self.chansync.data_out0.c[1]

milkymist/dvisampler/chansync.py

@@ -2,14 +2,15 @@ from migen.fhdl.structure import *
 from migen.fhdl.module import Module
 from migen.genlib.cdc import MultiReg
 from migen.genlib.fifo import SyncFIFO
+from migen.genlib.record import Record
 from migen.genlib.misc import optree
 from migen.bank.description import *
 
-_control_tokens = [0b1101010100, 0b0010101011, 0b0101010100, 0b1010101011]
+from milkymist.dvisampler.common import channel_layout
 
 class ChanSync(Module, AutoReg):
 	def __init__(self, nchan=3, depth=8):
-		self.char_synced = Signal()
+		self.valid_i = Signal()
 		self.chan_synced = Signal()
 
 		self._r_channels_synced = RegisterField(1, READ_ONLY, WRITE_ONLY)
@@ -18,10 +19,10 @@ class ChanSync(Module, AutoReg):
 		all_control_starts = Signal()
 		for i in range(nchan):
 			name = "data_in" + str(i)
-			data_in = Signal(10, name=name)
+			data_in = Record(channel_layout, name=name)
 			setattr(self, name, data_in)
 			name = "data_out" + str(i)
-			data_out = Signal(10, name=name)
+			data_out = Record(channel_layout, name=name)
 			setattr(self, name, data_out)
 
 			###
@@ -29,23 +30,23 @@ class ChanSync(Module, AutoReg):
 			fifo = SyncFIFO(10, depth)
 			self.add_submodule(fifo, "pix")
 			self.comb += [
-				fifo.we.eq(self.char_synced),
-				fifo.din.eq(data_in),
-				data_out.eq(fifo.dout)
+				fifo.we.eq(self.valid_i),
+				fifo.din.eq(Cat(*data_in.flatten())),
+				Cat(*data_out.flatten()).eq(fifo.dout)
 			]
 			is_control = Signal()
 			is_control_r = Signal()
-			self.sync.pix += If(fifo.re, is_control_r.eq(is_control))
+			self.sync.pix += If(fifo.readable & fifo.re, is_control_r.eq(is_control))
 			control_starts = Signal()
 			self.comb += [
-				is_control.eq(optree("|", [data_out == t for t in _control_tokens])),
+				is_control.eq(~data_out.de),
 				control_starts.eq(is_control & ~is_control_r),
 				fifo.re.eq(~is_control | all_control_starts)
 			]
 			lst_control_starts.append(control_starts)
 
 		self.comb += all_control_starts.eq(optree("&", lst_control_starts))
-		self.sync.pix += If(~self.char_synced,
+		self.sync.pix += If(~self.valid_i,
 				self.chan_synced.eq(0)
 			).Elif(all_control_starts, self.chan_synced.eq(1))
 		self.specials += MultiReg(self.chan_synced, self._r_channels_synced.field.w)

milkymist/dvisampler/charsync.py

@@ -4,7 +4,7 @@ from migen.genlib.cdc import MultiReg
 from migen.genlib.misc import optree
 from migen.bank.description import *
 
-_control_tokens = [0b1101010100, 0b0010101011, 0b0101010100, 0b1010101011]
+from milkymist.dvisampler.common import control_tokens
 
 class CharSync(Module, AutoReg):
 	def __init__(self, required_controls=8):
@@ -24,7 +24,7 @@ class CharSync(Module, AutoReg):
 		found_control = Signal()
 		control_position = Signal(max=10)
 		for i in range(10):
-			self.sync.pix += If(optree("|", [raw[i:i+10] == t for t in _control_tokens]),
+			self.sync.pix += If(optree("|", [raw[i:i+10] == t for t in control_tokens]),
 			  	found_control.eq(1),
 			  	control_position.eq(i)
 			)

milkymist/dvisampler/common.py

@@ -0,0 +1,2 @@
+control_tokens = [0b1101010100, 0b0010101011, 0b0101010100, 0b1010101011]
+channel_layout = [("d", 8), ("c", 2), ("de", 1)]

milkymist/dvisampler/decoding.py

@@ -1,57 +1,25 @@
 from migen.fhdl.structure import *
 from migen.fhdl.module import Module
+from migen.genlib.record import Record
 
-class _TMDSDecoding(Module):
-	def __init__(self):
-		self.input = Signal(10)
-		self.de = Signal()
-		self.data = Signal(8)
-		self.c = Signal(2)
-
-		###
-
-		self.sync.pix += self.de.eq(1)
-		for i, t in enumerate([0b1101010100, 0b0010101011, 0b0101010100, 0b1010101011]):
-			self.sync.pix += If(self.input == t,
-				self.de.eq(0),
-				self.c.eq(i)
-			)
-		self.sync.pix += self.data[0].eq(self.input[0] ^ self.input[9])
-		for i in range(1, 8):
-			self.sync.pix += self.data[i].eq(self.input[i] ^ self.input[i-1] ^ ~self.input[8])
+from milkymist.dvisampler.common import control_tokens, channel_layout
 
 class Decoding(Module):
 	def __init__(self):
 		self.valid_i = Signal()
-		self.data0 = Signal(10)
-		self.data1 = Signal(10)
-		self.data2 = Signal(10)
-
+		self.input = Signal(10)
 		self.valid_o = Signal()
-		self.de = Signal()
-		self.r = Signal(8)
-		self.g = Signal(8)
-		self.b = Signal(8)
-		self.hsync = Signal()
-		self.vsync = Signal()
+		self.output = Record(channel_layout)
 
 		###
 
-		self.submodules.decode0 = _TMDSDecoding()
-		self.submodules.decode1 = _TMDSDecoding()
-		self.submodules.decode2 = _TMDSDecoding()
-
-		self.comb += [
-			self.decode0.input.eq(self.data0),
-			self.decode1.input.eq(self.data1),
-			self.decode2.input.eq(self.data2),
-
-			self.de.eq(self.decode0.de),
-			self.r.eq(self.decode2.data),
-			self.g.eq(self.decode1.data),
-			self.b.eq(self.decode0.data),
-			self.hsync.eq(self.decode0.c[0]),
-			self.vsync.eq(self.decode0.c[1])
-		]
-
+		self.sync.pix += self.output.de.eq(1)
+		for i, t in enumerate(control_tokens):
+			self.sync.pix += If(self.input == t,
+				self.output.de.eq(0),
+				self.output.c.eq(i)
+			)
+		self.sync.pix += self.output.d[0].eq(self.input[0] ^ self.input[9])
+		for i in range(1, 8):
+			self.sync.pix += self.output.d[i].eq(self.input[i] ^ self.input[i-1] ^ ~self.input[8])
 		self.sync.pix += self.valid_o.eq(self.valid_i)