From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Mon, 15 Dec 2014 15:44:12 +0000 (+0100)
Subject: add simple synthetizable BIST
X-Git-Tag: 24jan2021_ls180~2572^2~115
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=707b43178ba3d80aa5a4b60ee13c78c4f6879fa9;p=litex.git

add simple synthetizable BIST
---

diff --git a/lib/sata/bist.py b/lib/sata/bist.py
new file mode 100644
index 00000000..2aed02fa
--- /dev/null
+++ b/lib/sata/bist.py
@@ -0,0 +1,91 @@
+from migen.fhdl.std import *
+from migen.genlib.fsm import FSM, NextState
+
+from lib.sata.common import *
+
+class SATABIST(Module):
+	def __init__(self, sector_size=512, max_count=1):
+		self.sink = sink = Sink(command_rx_description(32))
+		self.source = source = Source(command_tx_description(32))
+
+		self.start = Signal()
+		self.sector = Signal(48)
+		self.done = Signal()
+		self.errors = Signal(32)
+
+		errors = Signal(32)
+		inc_errors = Signal()
+		self.sync += \
+			If(self.start,
+				errors.eq(0),
+			).Elif(inc_errors,
+				errors.eq(errors+1)
+			)
+		self.comb += self.errors.eq(errors)
+
+		cnt = Signal(32)
+		inc_cnt = Signal()
+		clr_cnt = Signal()
+		self.sync += \
+			If(clr_cnt,
+				cnt.eq(0),
+			).Elif(inc_cnt,
+				cnt.eq(cnt+1)
+			)
+
+		fsm = FSM(reset_state="IDLE")
+		self.submodules += fsm
+
+		fsm.act("IDLE",
+			self.done.eq(1),
+			clr_cnt.eq(1),
+			If(self.start,
+				NextState("SEND_WRITE_CMD_AND_DATA")
+			)
+		)
+		fsm.act("SEND_WRITE_CMD_AND_DATA",
+			source.stb.eq(1),
+			source.sop.eq((cnt==0)),
+			source.eop.eq((cnt==(sector_size*max_count)//4-1)),
+			source.write.eq(1),
+			source.sector.eq(self.sector),
+			source.count.eq(max_count),
+			source.data.eq(cnt), #XXX use LFSR
+			inc_cnt.eq(source.ack),
+			If(source.stb & source.eop & source.ack,
+				NextState("WAIT_WRITE_ACK")
+			)
+		)
+		fsm.act("WAIT_WRITE_ACK",
+			sink.ack.eq(1),
+			If(sink.stb & sink.write,
+				NextState("SEND_READ_CMD")
+			)
+		)
+		fsm.act("SEND_READ_CMD",
+			source.stb.eq(1),
+			source.sop.eq(1),
+			source.eop.eq(1),
+			source.read.eq(1),
+			source.sector.eq(self.sector),
+			source.count.eq(max_count),
+			If(source.ack,
+				NextState("WAIT_READ_ACK")
+			)
+		)
+		fsm.act("WAIT_READ_ACK",
+			clr_cnt.eq(1),
+			If(sink.stb & sink.read,
+				NextState("RECEIVE_READ_DATA")
+			)
+		)
+		fsm.act("RECEIVE_READ_DATA",
+			sink.ack.eq(1),
+			inc_cnt.eq(sink.stb),
+			If(sink.stb & (sink.data != cnt), #XXX use LFSR
+				inc_errors.eq(1)
+			),
+			If(sink.stb & sink.eop,
+				NextState("IDLE")
+			)
+		)
diff --git a/lib/sata/test/Makefile b/lib/sata/test/Makefile
index ffee2fdd..ef772ae9 100644
--- a/lib/sata/test/Makefile
+++ b/lib/sata/test/Makefile
@@ -20,6 +20,9 @@ link_tb:
 command_tb:
 	$(CMD) command_tb.py
 
+bist_tb:
+	$(CMD) bist_tb.py
+
 all: crc_tb scrambler_tb link_tb command_tb
 
 clean:
diff --git a/lib/sata/test/bist_tb.py b/lib/sata/test/bist_tb.py
new file mode 100644
index 00000000..41d5af56
--- /dev/null
+++ b/lib/sata/test/bist_tb.py
@@ -0,0 +1,46 @@
+import random, copy
+
+from migen.fhdl.std import *
+from migen.genlib.record import *
+from migen.sim.generic import run_simulation
+
+from lib.sata.common import *
+from lib.sata.link import SATALink
+from lib.sata.transport import SATATransport
+from lib.sata.command import SATACommand
+from lib.sata.bist import SATABIST
+
+from lib.sata.test.hdd import *
+from lib.sata.test.common import *
+
+class TB(Module):
+	def __init__(self):
+		self.submodules.hdd = HDD(
+				link_debug=False, link_random_level=50,
+				transport_debug=False, transport_loopback=False,
+				hdd_debug=True)
+		self.submodules.link = SATALink(self.hdd.phy)
+		self.submodules.transport = SATATransport(self.link)
+		self.submodules.command = SATACommand(self.transport)
+		self.submodules.bist = SATABIST(sector_size=512, max_count=1)
+
+		self.comb += [
+			self.bist.source.connect(self.command.sink),
+			self.command.source.connect(self.bist.sink)
+		]
+
+	def gen_simulation(self, selfp):
+		hdd = self.hdd
+		hdd.malloc(0, 64)
+		while True:
+			selfp.bist.start = 1
+			yield
+			selfp.bist.start = 0
+			yield
+			while selfp.bist.done == 0:
+				yield
+			print("errors: {}".format(selfp.bist.errors))
+			selfp.bist.sector += 1
+
+if __name__ == "__main__":
+	run_simulation(TB(), ncycles=4096, vcd_name="my.vcd", keep_files=True)