dvisampler: channel synchronization

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.chansync import ChanSync
 
 class DVISampler(Module, AutoReg):
 	def __init__(self, inversions=""):
@@ -34,3 +35,12 @@ class DVISampler(Module, AutoReg):
 			charsync = CharSync()
 			setattr(self.submodules, name + "_charsync", charsync)
 			self.comb += charsync.raw_data.eq(cap.d)
+
+		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),
+		]

milkymist/dvisampler/chansync.py

@@ -0,0 +1,51 @@
+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.misc import optree
+from migen.bank.description import *
+
+_control_tokens = [0b1101010100, 0b0010101011, 0b0101010100, 0b1010101011]
+
+class ChanSync(Module, AutoReg):
+	def __init__(self, nchan=3, depth=8):
+		self.char_synced = Signal()
+		self.chan_synced = Signal()
+
+		self._r_channels_synced = RegisterField(1, READ_ONLY, WRITE_ONLY)
+
+		lst_control_starts = []
+		all_control_starts = Signal()
+		for i in range(nchan):
+			name = "data_in" + str(i)
+			data_in = Signal(10, name=name)
+			setattr(self, name, data_in)
+			name = "data_out" + str(i)
+			data_out = Signal(10, name=name)
+			setattr(self, name, data_out)
+
+			###
+		
+			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)
+			]
+			is_control = Signal()
+			is_control_r = Signal()
+			self.sync.pix += If(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])),
+				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.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

@@ -9,7 +9,7 @@ _control_tokens = [0b1101010100, 0b0010101011, 0b0101010100, 0b1010101011]
 class CharSync(Module, AutoReg):
 	def __init__(self, required_controls=8):
 		self.raw_data = Signal(10)
-		self.char_synced = Signal()
+		self.synced = Signal()
 		self.data = Signal(10)
 
 		self._r_char_synced = RegisterField(1, READ_ONLY, WRITE_ONLY)
@@ -36,7 +36,7 @@ class CharSync(Module, AutoReg):
 			If(found_control & (control_position == previous_control_position),
 				If(control_counter == (required_controls - 1),
 					control_counter.eq(0),
-					self.char_synced.eq(1),
+					self.synced.eq(1),
 					word_sel.eq(control_position)
 				).Else(
 					control_counter.eq(control_counter + 1)
@@ -46,6 +46,6 @@ class CharSync(Module, AutoReg):
 			),
 			previous_control_position.eq(control_position)
 		]
-		self.specials += MultiReg(self.char_synced, self._r_char_synced.field.w)
+		self.specials += MultiReg(self.synced, self._r_char_synced.field.w)
 
 		self.sync.pix += self.data.eq(raw >> word_sel)

software/include/hw/dvisampler.h

@@ -27,6 +27,8 @@
 #define CSR_DVISAMPLER0_D2_PHASE_RESET	DVISAMPLER0_CSR(0x3C)
 #define CSR_DVISAMPLER0_D2_CHAR_SYNCED	DVISAMPLER0_CSR(0x40)
 
+#define CSR_DVISAMPLER0_CHAN_SYNCED	DVISAMPLER0_CSR(0x44)
+
 #define DVISAMPLER_DELAY_CAL		0x01
 #define DVISAMPLER_DELAY_RST		0x02
 #define DVISAMPLER_DELAY_INC		0x04

software/videomixer/main.c

@@ -60,10 +60,11 @@ static void adjust_phase(void)
 			CSR_DVISAMPLER0_D2_PHASE_RESET = 1;
 			break;
 	}
-	printf("Ph: %4d %4d %4d // %d%d%d\n", d0, d1, d2,
+	printf("Ph: %4d %4d %4d // %d%d%d // %d\n", d0, d1, d2,
 		CSR_DVISAMPLER0_D0_CHAR_SYNCED,
 		CSR_DVISAMPLER0_D1_CHAR_SYNCED,
-		CSR_DVISAMPLER0_D2_CHAR_SYNCED);
+		CSR_DVISAMPLER0_D2_CHAR_SYNCED,
+		CSR_DVISAMPLER0_CHAN_SYNCED);
 }
 
 static void vmix(void)