dvisampler: character synchronization

milkymist/dvisampler/__init__.py

@@ -5,6 +5,7 @@ from migen.bank.description import *
 from milkymist.dvisampler.edid import EDID
 from milkymist.dvisampler.clocking import Clocking
 from milkymist.dvisampler.datacapture import DataCapture
+from milkymist.dvisampler.charsync import CharSync
 
 class DVISampler(Module, AutoReg):
 	def __init__(self, inversions=""):
@@ -18,13 +19,18 @@ class DVISampler(Module, AutoReg):
 		for datan in "012":
 			name = "data" + str(datan)
 			invert = datan in inversions
+			
+			signame = name + "_n" if invert else name
+			s = Signal(name=signame)
+			setattr(self, signame, s)
+
 			cap = DataCapture(8, invert)
 			setattr(self.submodules, name + "_cap", cap)
-			if invert:
-				name += "_n"
-			s = Signal(name=name)
-			setattr(self, name, s)
 			self.comb += [
 				cap.pad.eq(s),
 				cap.serdesstrobe.eq(self.clocking.serdesstrobe)
 			]
+
+			charsync = CharSync()
+			setattr(self.submodules, name + "_charsync", charsync)
+			self.comb += charsync.raw_data.eq(cap.d)

milkymist/dvisampler/charsync.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.misc import optree
+from migen.bank.description import *
+
+_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.data = Signal(10)
+
+		self._r_char_synced = RegisterField(1, READ_ONLY, WRITE_ONLY)
+
+		###
+
+		raw_data1 = Signal(10)
+		self.sync.pix += raw_data1.eq(self.raw_data)
+		raw = Signal(20)
+		self.comb += raw.eq(Cat(raw_data1, self.raw_data))
+
+		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]),
+			  	found_control.eq(1),
+			  	control_position.eq(i)
+			)
+
+		control_counter = Signal(max=required_controls)
+		previous_control_position = Signal(max=10)
+		word_sel = Signal(max=10)
+		self.sync.pix += [
+			If(found_control & (control_position == previous_control_position),
+				If(control_counter == (required_controls - 1),
+					control_counter.eq(0),
+					self.char_synced.eq(1),
+					word_sel.eq(control_position)
+				).Else(
+					control_counter.eq(control_counter + 1)
+				)
+			).Else(
+				control_counter.eq(0)
+			),
+			previous_control_position.eq(control_position)
+		]
+		self.specials += MultiReg(self.char_synced, self._r_char_synced.field.w)
+
+		self.sync.pix += self.data.eq(raw >> word_sel)

software/include/hw/dvisampler.h

@@ -13,16 +13,19 @@
 #define CSR_DVISAMPLER0_D0_DELAY_BUSY	DVISAMPLER0_CSR(0x0C)
 #define CSR_DVISAMPLER0_D0_PHASE	DVISAMPLER0_CSR(0x10)
 #define CSR_DVISAMPLER0_D0_PHASE_RESET	DVISAMPLER0_CSR(0x14)
+#define CSR_DVISAMPLER0_D0_CHAR_SYNCED	DVISAMPLER0_CSR(0x18)
 
-#define CSR_DVISAMPLER0_D1_DELAY_CTL	DVISAMPLER0_CSR(0x18)
+#define CSR_DVISAMPLER0_D1_DELAY_CTL	DVISAMPLER0_CSR(0x1C)
-#define CSR_DVISAMPLER0_D1_DELAY_BUSY	DVISAMPLER0_CSR(0x1C)
+#define CSR_DVISAMPLER0_D1_DELAY_BUSY	DVISAMPLER0_CSR(0x20)
-#define CSR_DVISAMPLER0_D1_PHASE	DVISAMPLER0_CSR(0x20)
+#define CSR_DVISAMPLER0_D1_PHASE	DVISAMPLER0_CSR(0x24)
-#define CSR_DVISAMPLER0_D1_PHASE_RESET	DVISAMPLER0_CSR(0x24)
+#define CSR_DVISAMPLER0_D1_PHASE_RESET	DVISAMPLER0_CSR(0x28)
+#define CSR_DVISAMPLER0_D1_CHAR_SYNCED	DVISAMPLER0_CSR(0x2C)
 
-#define CSR_DVISAMPLER0_D2_DELAY_CTL	DVISAMPLER0_CSR(0x28)
+#define CSR_DVISAMPLER0_D2_DELAY_CTL	DVISAMPLER0_CSR(0x30)
-#define CSR_DVISAMPLER0_D2_DELAY_BUSY	DVISAMPLER0_CSR(0x2C)
+#define CSR_DVISAMPLER0_D2_DELAY_BUSY	DVISAMPLER0_CSR(0x34)
-#define CSR_DVISAMPLER0_D2_PHASE	DVISAMPLER0_CSR(0x30)
+#define CSR_DVISAMPLER0_D2_PHASE	DVISAMPLER0_CSR(0x38)
-#define CSR_DVISAMPLER0_D2_PHASE_RESET	DVISAMPLER0_CSR(0x34)
+#define CSR_DVISAMPLER0_D2_PHASE_RESET	DVISAMPLER0_CSR(0x3C)
+#define CSR_DVISAMPLER0_D2_CHAR_SYNCED	DVISAMPLER0_CSR(0x40)
 
 #define DVISAMPLER_DELAY_CAL		0x01
 #define DVISAMPLER_DELAY_RST		0x02

software/videomixer/main.c

@@ -60,7 +60,10 @@ static void adjust_phase(void)
 			CSR_DVISAMPLER0_D2_PHASE_RESET = 1;
 			break;
 	}
-	//printf("Ph: %4d %4d %4d\n", d0, d1, d2);
+	printf("Ph: %4d %4d %4d // %d%d%d\n", d0, d1, d2,
+		CSR_DVISAMPLER0_D0_CHAR_SYNCED,
+		CSR_DVISAMPLER0_D1_CHAR_SYNCED,
+		CSR_DVISAMPLER0_D2_CHAR_SYNCED);
 }
 
 static void vmix(void)