From 3162949f82856d93bd859f69f9088ac9b12cce38 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sebastien@milkymist.org>
Date: Thu, 11 Jul 2013 18:31:38 +0200
Subject: [PATCH] memtest: add DMA cores

---
 milkymist/memtest/__init__.py | 67 +++++++++++++++++++++++++++++++++--
 1 file changed, 65 insertions(+), 2 deletions(-)

diff --git a/milkymist/memtest/__init__.py b/milkymist/memtest/__init__.py
index dcc05f8a2..7434cd55d 100644
--- a/milkymist/memtest/__init__.py
+++ b/milkymist/memtest/__init__.py
@@ -1,10 +1,13 @@
 from migen.fhdl.std import *
 from migen.genlib.misc import optree
-from migen.fhdl import verilog
+from migen.bank.description import *
+from migen.actorlib import dma_lasmi
+from migen.actorlib.spi import MODE_SINGLE_SHOT, DMAReadController, DMAWriteController
 
 class LFSR(Module):
 	def __init__(self, n_out, n_state=31, taps=[27, 30]):
 		self.ce = Signal()
+		self.reset = Signal()
 		self.o = Signal(n_out)
 
 		###
@@ -17,12 +20,16 @@ class LFSR(Module):
 			curval.insert(0, nv)
 			curval.pop()
 
-		self.sync += If(self.ce,
+		self.sync += If(self.reset,
+				state.eq(0),
+				self.o.eq(0)
+			).Elif(self.ce,
 				state.eq(Cat(*curval[:n_state])),
 				self.o.eq(Cat(*curval))
 			)
 
 def _print_lfsr_code():
+	from migen.fhdl import verilog
 	dut = LFSR(3, 4, [3, 2])
 	print(verilog.convert(dut, ios={dut.ce, dut.o}))
 
@@ -40,6 +47,62 @@ def _sim_lfsr():
 	sim = Simulator(tb)
 	sim.run(20)
 
+memtest_magic = 0x361f
+
+class MemtestWriter(Module):
+	def __init__(self, lasmim):
+		self._r_magic = CSRStatus(16)
+		self._r_reset = CSR()
+		self.submodules._dma = DMAWriteController(dma_lasmi.Writer(lasmim), MODE_SINGLE_SHOT)
+
+		###
+
+		self.comb += self._r_magic.status.eq(memtest_magic)
+
+		lfsr = LFSR(lasmim.dw)
+		self.submodules += lfsr
+		self.comb += lfsr.reset.eq(self._r_reset.re)
+
+		self.comb += [
+			self._dma.data.stb.eq(1),
+			lfsr.ce.eq(self._dma.data.ack),
+			self._dma.data.payload.d.eq(lfsr.o)
+		]
+
+	def get_csrs(self):
+		return [self._r_magic, self._r_reset] + self._dma.get_csrs()
+
+class MemtestReader(Module):
+	def __init__(self, lasmim):
+		self._r_magic = CSRStatus(16)
+		self._r_reset = CSR()
+		self._r_error_count = CSRStatus(lasmim.aw)
+		self.submodules._dma = DMAReadController(dma_lasmi.Reader(lasmim), MODE_SINGLE_SHOT)
+
+		###
+
+		self.comb += self._r_magic.status.eq(memtest_magic)
+
+		lfsr = LFSR(lasmim.dw)
+		self.submodules += lfsr
+		self.comb += lfsr.reset.eq(self._r_reset.re)
+
+		self.comb += [
+			lfsr.ce.eq(self._dma.data.stb),
+			self._dma.data.ack.eq(1)
+		]
+		err_cnt = self._r_error_count.status
+		self.sync += [
+			If(self._r_reset.re,
+				err_cnt.eq(0)
+			).Elif(self._dma.data.stb,
+				If(self._dma.data.payload.d != lfsr.o, err_cnt.eq(err_cnt + 1))
+			)
+		]
+
+	def get_csrs(self):
+		return [self._r_magic, self._r_reset, self._r_error_count] + self._dma.get_csrs()
+
 if __name__ == "__main__":
 	_print_lfsr_code()
 	_sim_lfsr()