From fd0e281dfc15b2fb15f8a7f9ae1a1ceab7561a24 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sebastien@milkymist.org>
Date: Fri, 3 Aug 2012 18:49:04 +0200
Subject: [PATCH] flow: in-system debugger module

---
 migen/flow/isd.py | 84 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 migen/flow/isd.py

diff --git a/migen/flow/isd.py b/migen/flow/isd.py
new file mode 100644
index 000000000..36c893fc2
--- /dev/null
+++ b/migen/flow/isd.py
@@ -0,0 +1,84 @@
+from migen.fhdl.structure import *
+from migen.bank.description import *
+from migen.flow.hooks import DFGHook
+
+ISD_MAGIC = 0x6ab4
+
+# TODO: add freeze
+class EndpointReporter:
+	def __init__(self, endpoint, nbits):
+		self.endpoint = endpoint
+		self.reset = Signal()
+		
+		self._ack_count = RegisterField("ack_count", nbits, access_bus=READ_ONLY, access_dev=WRITE_ONLY)
+		self._nack_count = RegisterField("nack_count", nbits, access_bus=READ_ONLY, access_dev=WRITE_ONLY)
+		self._cur_stb = Field("cur_stb", 1, access_bus=READ_ONLY, access_dev=WRITE_ONLY)
+		self._cur_ack = Field("cur_ack", 1, access_bus=READ_ONLY, access_dev=WRITE_ONLY)
+		self._cur_status = RegisterFields("cur_status", [self._cur_stb, self._cur_ack])
+	
+	def get_registers(self):
+		return [self._ack_count, self._nack_count, self._cur_status]
+	
+	def get_fragment(self):
+		stb = Signal()
+		ack = Signal()
+		ack_count = self._ack_count.field.w
+		nack_count = self._nack_count.field.w
+		comb = [
+			self._cur_stb.w.eq(stb),
+			self._cur_ack.w.eq(ack)
+		]
+		sync = [
+			# register monitored signals
+			stb.eq(self.endpoint.stb),
+			ack.eq(self.endpoint.ack),
+			# count operations
+			If(self.reset,
+				ack_count.eq(0),
+				nack_count.eq(0)
+			).Else(
+				If(stb,
+					If(ack,
+						ack_count.eq(ack_count + 1)
+					).Else(
+						nack_count.eq(nack_count + 1)
+					)
+				)
+			)
+		]
+		return Fragment(comb, sync)
+
+class DFGReporter(DFGHook):
+	def __init__(self, dfg, nbits):
+		self._nbits = nbits
+		
+		self._r_magic = RegisterField("magic", 16, access_bus=READ_ONLY, access_dev=WRITE_ONLY)
+		self._r_neps = RegisterField("neps", 8, access_bus=READ_ONLY, access_dev=WRITE_ONLY)
+		self._r_nbits = RegisterField("nbits", 8, access_bus=READ_ONLY, access_dev=WRITE_ONLY)
+		self._r_reset = RegisterRaw("reset", 1)
+		
+		self.order = []
+		super().__init__(dfg, self._create)
+	
+	def _create(self, u, ep, v):
+		self.order.append((u, ep, v))
+		return EndpointReporter(u.actor.endpoints[ep], self._nbits)
+	
+	def print_map(self):
+		for n, (u, ep, v) in enumerate(self.order):
+			print("#" + str(n) + ": " + str(u) + ":" + ep + "  ->  " + str(v))
+	
+	def get_registers(self):
+		registers = [self._r_magic, self._r_neps, self._r_nbits, self._r_reset]
+		for u, ep, v in self.order:
+			registers += self.nodepair_to_ep[(u, v)][ep].get_registers()
+		return registers
+	
+	def get_fragment(self):
+		comb = [
+			self._r_magic.field.w.eq(ISD_MAGIC),
+			self._r_neps.field.w.eq(len(self.order)),
+			self._r_nbits.field.w.eq(self._nbits)
+		]
+		comb += [h.reset.eq(self._r_reset.re) for h in self.hooks_iter()]
+		return Fragment(comb) + super().get_fragment()