From 8160ced2e9ce96b4fba3c109a3ca16c7734ff83f Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sebastien@milkymist.org>
Date: Tue, 6 Mar 2012 19:29:39 +0100
Subject: [PATCH] sim: memory access

---
 examples/basic_sim.py   |  6 +++---
 examples/memory_sim.py  | 27 +++++++++++++++++++++++++++
 migen/fhdl/structure.py |  4 ++--
 migen/sim/generic.py    | 40 +++++++++++++++++++++++++---------------
 migen/sim/ipc.py        | 24 ++++++++++++++++++++----
 vpi/ipc.c               | 13 +++++++++----
 vpi/ipc.h               |  4 ++--
 vpi/main.c              | 12 ++++++++++--
 8 files changed, 98 insertions(+), 32 deletions(-)
 create mode 100644 examples/memory_sim.py

diff --git a/examples/basic_sim.py b/examples/basic_sim.py
index 3578bc97..a4f17c46 100644
--- a/examples/basic_sim.py
+++ b/examples/basic_sim.py
@@ -7,12 +7,12 @@ class Counter:
 		self.ce = Signal()
 		self.count = Signal(BV(37, True), reset=-5)
 	
-	def do_simulation(self, s, cycle):
-		if cycle % 2:
+	def do_simulation(self, s):
+		if s.cycle_counter % 2:
 			s.wr(self.ce, 0)
 		else:
 			s.wr(self.ce, 1)
-		print("Cycle: " + str(cycle) + " Count: " + str(s.rd(self.count)))
+		print("Cycle: " + str(s.cycle_counter) + " Count: " + str(s.rd(self.count)))
 	
 	def get_fragment(self):
 		sync = [If(self.ce, self.count.eq(self.count + 1))]
diff --git a/examples/memory_sim.py b/examples/memory_sim.py
new file mode 100644
index 00000000..7c58b2bb
--- /dev/null
+++ b/examples/memory_sim.py
@@ -0,0 +1,27 @@
+from migen.fhdl.structure import *
+from migen.sim.generic import Simulator, TopLevel
+from migen.sim.icarus import Runner
+
+class Mem:
+	def __init__(self):
+		self.a = Signal(BV(12))
+		self.d = Signal(BV(16))
+		p = MemoryPort(self.a, self.d)
+		self.mem = Memory(16, 2**12, p, init=list(range(20)))
+	
+	def do_simulation(self, s):
+		if s.cycle_counter >= 0:
+			value = s.rd(self.mem, s.cycle_counter)
+			print(value)
+			if value == 10:
+				s.interrupt = True
+	
+	def get_fragment(self):
+		return Fragment(memories=[self.mem], sim=[self.do_simulation])
+
+def main():
+	dut = Mem()
+	sim = Simulator(dut.get_fragment(), Runner())
+	sim.run()
+
+main()
diff --git a/migen/fhdl/structure.py b/migen/fhdl/structure.py
index 21e5cb0e..e5730ff5 100644
--- a/migen/fhdl/structure.py
+++ b/migen/fhdl/structure.py
@@ -276,6 +276,6 @@ class Fragment:
 			self.pads | other.pads,
 			self.sim + other.sim)
 
-	def call_sim(self, simulator, cycle):
+	def call_sim(self, simulator):
 		for s in self.sim:
-			s(simulator, cycle)
+			s(simulator)
diff --git a/migen/sim/generic.py b/migen/sim/generic.py
index 60057e1e..dddc7e41 100644
--- a/migen/sim/generic.py
+++ b/migen/sim/generic.py
@@ -84,7 +84,7 @@ class Simulator:
 			rst_signal=rst_signal,
 			return_ns=True)
 		
-		self.cycle_counter = 0
+		self.cycle_counter = -1
 		self.interrupt = False
 
 		self.sim_runner = sim_runner
@@ -92,36 +92,46 @@ class Simulator:
 		self.ipc.accept()
 		reply = self.ipc.recv()
 		assert(isinstance(reply, MessageTick))
-		self.fragment.call_sim(self, -1)
+		self.fragment.call_sim(self)
 	
 	def run(self, ncycles=-1):
+		self.interrupt = False
 		counter = 0
 		while not self.interrupt and (ncycles < 0 or counter < ncycles):
+			self.cycle_counter += 1
+			counter += 1
 			self.ipc.send(MessageGo())
 			reply = self.ipc.recv()
 			assert(isinstance(reply, MessageTick))
-			self.fragment.call_sim(self, self.cycle_counter)
-			self.cycle_counter += 1
-			counter += 1
+			self.fragment.call_sim(self)
 
-	def rd(self, signal):
+	def rd(self, item, index=0):
 		name = self.top_level.top_name + "." \
 		  + self.top_level.dut_name + "." \
-		  + self.namespace.get_name(signal)
-		self.ipc.send(MessageRead(name))
+		  + self.namespace.get_name(item)
+		self.ipc.send(MessageRead(name, Int32(index)))
 		reply = self.ipc.recv()
 		assert(isinstance(reply, MessageReadReply))
-		nbits = signal.bv.width
+		if isinstance(item, Memory):
+			signed = False
+			nbits = item.width
+		else:
+			signed = item.bv.signed
+			nbits = item.bv.width
 		value = reply.value & (2**nbits - 1)
-		if signal.bv.signed and (value & 2**(nbits - 1)):
+		if signed and (value & 2**(nbits - 1)):
 			value -= 2**nbits
 		return value
 	
-	def wr(self, signal, value):
+	def wr(self, item, value, index=0):
 		name = self.top_level.top_name + "." \
 		  + self.top_level.dut_name + "." \
-		  + self.namespace.get_name(signal)
+		  + self.namespace.get_name(item)
+		if isinstance(item, Memory):
+			nbits = item.width
+		else:
+			nbits = item.bv.width
 		if value < 0:
-			value += 2**signal.bv.width
-		assert(value >= 0 and value < 2**signal.bv.width)
-		self.ipc.send(MessageWrite(name, value))
+			value += 2**nbits
+		assert(value >= 0 and value < 2**nbits)
+		self.ipc.send(MessageWrite(name, Int32(index), value))
diff --git a/migen/sim/ipc.py b/migen/sim/ipc.py
index 9464a12c..ca59c4f7 100644
--- a/migen/sim/ipc.py
+++ b/migen/sim/ipc.py
@@ -5,6 +5,9 @@ import os
 # Message classes
 #
 
+class Int32(int):
+	pass
+
 class Message:
 	def __init__(self, *pvalues):
 		for parameter, value in zip(self.parameters, pvalues):
@@ -29,11 +32,11 @@ class MessageGo(Message):
 
 class MessageWrite(Message):
 	code = 2
-	parameters = [(str, "name"), (int, "value")]
+	parameters = [(str, "name"), (Int32, "index"), (int, "value")]
 
 class MessageRead(Message):
 	code = 3
-	parameters = [(str, "name")]
+	parameters = [(str, "name"), (Int32, "index")]
 
 class MessageReadReply(Message):
 	code = 4
@@ -58,6 +61,14 @@ def _pack_str(v):
 	p.append(0)
 	return p
 
+def _pack_int32(v):
+	return [
+		v & 0xff,
+		(v & 0xff00) >> 8,
+		(v & 0xff0000) >> 16,
+		(v & 0xff000000) >> 24
+	]
+
 def _pack(message):
 	r = [message.code]
 	for t, p in message.parameters:
@@ -67,6 +78,8 @@ def _pack(message):
 			r += _pack_int(value)
 		elif t == str:
 			r += _pack_str(value)
+		elif t == Int32:
+			r += _pack_int32(value)
 		else:
 			raise TypeError
 	return bytes(r)
@@ -75,10 +88,11 @@ def _pack(message):
 # Unpacking
 #
 
-def _unpack_int(i):
+def _unpack_int(i, nchunks=None):
 	v = 0
 	power = 1
-	nchunks = next(i)
+	if nchunks is None:
+		nchunks = next(i)
 	for j in range(nchunks):
 		v += power*next(i)
 		power *= 256
@@ -102,6 +116,8 @@ def _unpack(message):
 			v = _unpack_int(i)
 		elif t == str:
 			v = _unpack_str(i)
+		elif t == Int32:
+			v = _unpack_int(i, 4)
 		else:
 			raise TypeError
 		pvalues.append(v)
diff --git a/vpi/ipc.c b/vpi/ipc.c
index c78fd20e..c76081d3 100644
--- a/vpi/ipc.c
+++ b/vpi/ipc.c
@@ -90,24 +90,29 @@ int ipc_receive(struct ipc_softc *sc)
 			char *name;
 			int nchunks;
 			unsigned char *chunks;
+			unsigned int index;
 			
 			name = &buffer[i];
 			i += strlen(name) + 1;
-			assert(i < l);
+			assert((i+4) < l);
+			index = buffer[i] | buffer[i+1] << 8 | buffer[i+2] << 16 | buffer[i+3] << 24;
+			i += 4;
 			nchunks = buffer[i++];
 			assert(i + nchunks == l);
 			chunks = (unsigned char *)&buffer[i];
 			
-			return sc->h_write(name, nchunks, chunks, sc->user);
+			return sc->h_write(name, index, nchunks, chunks, sc->user);
 		}
 		case MESSAGE_READ: {
 			char *name;
+			unsigned int index;
 			
 			name = &buffer[i];
 			i += strlen(name) + 1;
-			assert(i == l);
+			assert((i+4) == l);
+			index = buffer[i] | buffer[i+1] << 8 | buffer[i+2] << 16 | buffer[i+3] << 24;
 			
-			return sc->h_read(name, sc->user);
+			return sc->h_read(name, index, sc->user);
 		}
 		default:
 			return 0;
diff --git a/vpi/ipc.h b/vpi/ipc.h
index ba07ede5..baad5647 100644
--- a/vpi/ipc.h
+++ b/vpi/ipc.h
@@ -4,8 +4,8 @@
 struct ipc_softc;
 
 typedef int(*go_handler)(void *);
-typedef int(*write_handler)(char *, int, const unsigned char *, void *);
-typedef int(*read_handler)(char *, void *);
+typedef int(*write_handler)(char *, int, int, const unsigned char *, void *);
+typedef int(*read_handler)(char *, int, void *);
 
 struct ipc_softc *ipc_connect(const char *sockaddr, 
 	go_handler h_go, write_handler h_write, read_handler h_read, void *user);
diff --git a/vpi/main.c b/vpi/main.c
index 0157df1f..324be66d 100644
--- a/vpi/main.c
+++ b/vpi/main.c
@@ -23,7 +23,7 @@ static s_vpi_time zero_delay = {
 	.low = 0
 };
 
-static int h_write(char *name, int nchunks, const unsigned char *chunks, void *user)
+static int h_write(char *name, int index, int nchunks, const unsigned char *chunks, void *user)
 {
 	vpiHandle item;
 	s_vpi_vecval vector[64];
@@ -35,6 +35,10 @@ static int h_write(char *name, int nchunks, const unsigned char *chunks, void *u
 		fprintf(stderr, "Attempted to write non-existing signal %s\n", name);
 		return 0;
 	}
+	if(vpi_get(vpiType, item) == vpiMemory)
+		item = vpi_handle_by_index(item, index);
+	else
+		assert(index == 0);
 	
 	assert(nchunks <= 255);
 	for(i=0;i<64;i++) {
@@ -51,7 +55,7 @@ static int h_write(char *name, int nchunks, const unsigned char *chunks, void *u
 	return 1;
 }
 
-static int h_read(char *name, void *user)
+static int h_read(char *name, int index, void *user)
 {
 	struct migensim_softc *sc = (struct migensim_softc *)user;
 	vpiHandle item;
@@ -68,6 +72,10 @@ static int h_read(char *name, void *user)
 		fprintf(stderr, "Attempted to read non-existing signal %s\n", name);
 		return 0;
 	}
+	if(vpi_get(vpiType, item) == vpiMemory)
+		item = vpi_handle_by_index(item, index);
+	else
+		assert(index == 0);
 	
 	value.format = vpiVectorVal;
 	vpi_get_value(item, &value);
-- 
2.30.2