Merge pull request #2 from enjoy-digital/master

update with hyperram and other changes
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Antti Lukats 2019-08-16 14:36:59 +02:00 committed by GitHub
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2 changed files with 190 additions and 0 deletions

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litex/soc/cores/hyperbus.py Normal file
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# This file is Copyright (c) 2019 Antti Lukats <antti.lukats@gmail.com>
# This file is Copyright (c) 2019 Florent Kermarrec <florent@enjoy-digital.fr>
# License: BSD
from migen import *
from migen.genlib.misc import timeline
from migen.genlib.io import DifferentialOutput
from litex.soc.interconnect import wishbone
# HyperRAM -----------------------------------------------------------------------------------------
class HyperRAM(Module):
"""HyperRAM
Provides a very simple/minimal HyperRAM core that should work with all FPGA/HyperRam chips:
- FPGA vendor agnostic.
- no setup/chip configuration (use default latency).
This core favrors portability and ease of use over performance.
"""
def __init__(self, pads):
self.pads = pads
self.bus = bus = wishbone.Interface()
# # #
clk = Signal()
clk_phase = Signal(2)
cs = Signal()
ca = Signal(48)
sr = Signal(48)
dq = self.add_tristate(pads.dq) if not hasattr(pads.dq, "oe") else pads.dq
rwds = self.add_tristate(pads.rwds) if not hasattr(pads.rwds, "oe") else pads.rwds
# Drive rst_n, cs_n, clk from internal signals ---------------------------------------------
if hasattr(pads, "rst_n"):
self.comb += pads.rst_n.eq(1)
self.comb += pads.cs_n[0].eq(~cs)
assert len(pads.cs_n) <= 2
if len(pads.cs_n) == 2:
self.comb += pads.cs_n[1].eq(1)
if hasattr(pads, "clk"):
self.comb += pads.clk.eq(clk)
else:
self.specials += DifferentialOutput(clk, pads.clk_p, pads.clk_n)
# Clock Generation (sys_clk/4) -------------------------------------------------------------
self.sync += clk_phase.eq(clk_phase + 1)
cases = {}
cases[1] = clk.eq(cs) # Set pads clk on 90° (if cs is set)
cases[3] = clk.eq(0) # Clear pads clk on 270°
self.sync += Case(clk_phase, cases)
# Data Shift Register (for write and read) -------------------------------------------------
dqi = Signal(8)
self.sync += dqi.eq(dq.i) # Sample on 90° and 270°
cases = {}
cases[0] = sr.eq(Cat(dqi, sr[:-8])) # Shift on 0°
cases[2] = sr.eq(Cat(dqi, sr[:-8])) # Shift on 180°
self.sync += Case(clk_phase, cases)
self.comb += [
bus.dat_r.eq(sr), # To Wisbone
dq.o.eq(sr[-8:]), # To HyperRAM
]
# Command generation -----------------------------------------------------------------------
self.comb += [
ca[47].eq(~self.bus.we), # R/W#
ca[45].eq(1), # Burst Type (Linear)
ca[16:35].eq(self.bus.adr[2:21]), # Row & Upper Column Address
ca[1:3].eq(self.bus.adr[0:2]), # Lower Column Address
ca[0].eq(0), # Lower Column Address
]
# Sequencer --------------------------------------------------------------------------------
dt_seq = [
# DT, Action
(3, []),
(12, [cs.eq(1), dq.oe.eq(1), sr.eq(ca)]), # Command: 6 clk
(44, [dq.oe.eq(0)]), # Latency(default): 2*6 clk
(2, [dq.oe.eq(self.bus.we), # Write/Read data byte: 2 clk
sr[:16].eq(0),
sr[16:].eq(self.bus.dat_w),
rwds.oe.eq(self.bus.we),
rwds.o.eq(~bus.sel[0])]),
(2, [rwds.o.eq(~bus.sel[1])]), # Write/Read data byte: 2 clk
(2, [rwds.o.eq(~bus.sel[2])]), # Write/Read data byte: 2 clk
(2, [rwds.o.eq(~bus.sel[3])]), # Write/Read data byte: 2 clk
(2, [cs.eq(0), rwds.oe.eq(0), dq.oe.eq(0)]),
(1, [bus.ack.eq(1)]),
(1, [bus.ack.eq(0)]),
(0, []),
]
# Convert delta-time sequencer to time sequencer
t_seq = []
t_seq_start = (clk_phase == 1)
t = 0
for dt, a in dt_seq:
t_seq.append((t, a))
t += dt
self.sync += timeline(bus.cyc & bus.stb & t_seq_start, t_seq)
def add_tristate(self, pad):
t = TSTriple(len(pad))
self.specials += t.get_tristate(pad)
return t

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test/test_hyperbus.py Normal file
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# This file is Copyright (c) 2019 Florent Kermarrec <florent@enjoy-digital.fr>
# License: BSD
import unittest
from migen import *
from litex.soc.cores.hyperbus import HyperRAM
def c2bool(c):
return {"-": 1, "_": 0}[c]
class Pads: pass
class HyperRamPads:
def __init__(self):
self.clk = Signal()
self.cs_n = Signal()
self.dq = Record([("oe", 1), ("o", 8), ("i", 8)])
self.rwds = Record([("oe", 1), ("o", 1), ("i", 1)])
class TestHyperBus(unittest.TestCase):
def test_hyperram_syntax(self):
pads = Record([("clk", 1), ("cs_n", 1), ("dq", 8), ("rwds", 1)])
hyperram = HyperRAM(pads)
pads = Record([("clk_p", 1), ("clk_n", 1), ("cs_n", 1), ("dq", 8), ("rwds", 1)])
hyperram = HyperRAM(pads)
def test_hyperram_write(self):
def fpga_gen(dut):
yield from dut.bus.write(0x1234, 0xdeadbeef)
yield
def hyperram_gen(dut):
clk = "___--__--__--__--__--__--__--__--__--__--__--__--__--__--__--__--_______"
cs_n = "--________________________________________________________________------"
dq_oe = "__------------____________________________________________--------______"
dq_o = "002000048d000000000000000000000000000000000000000000000000deadbeef000000"
rwds_oe = "__________________________________________________________--------______"
rwds_o = "________________________________________________________________________"
for i in range(3):
yield
for i in range(len(clk)):
self.assertEqual(c2bool(clk[i]), (yield dut.pads.clk))
self.assertEqual(c2bool(cs_n[i]), (yield dut.pads.cs_n))
self.assertEqual(c2bool(dq_oe[i]), (yield dut.pads.dq.oe))
self.assertEqual(int(dq_o[2*(i//2):2*(i//2)+2], 16), (yield dut.pads.dq.o))
self.assertEqual(c2bool(rwds_oe[i]), (yield dut.pads.rwds.oe))
self.assertEqual(c2bool(rwds_o[i]), (yield dut.pads.rwds.o))
yield
dut = HyperRAM(HyperRamPads())
run_simulation(dut, [fpga_gen(dut), hyperram_gen(dut)])
def test_hyperram_read(self):
def fpga_gen(dut):
dat = yield from dut.bus.read(0x1234)
self.assertEqual(dat, 0xdeadbeef)
def hyperram_gen(dut):
clk = "___--__--__--__--__--__--__--__--__--__--__--__--__--__--__--__--_______"
cs_n = "--________________________________________________________________------"
dq_oe = "__------------__________________________________________________________"
dq_o = "00a000048d00000000000000000000000000000000000000000000000000000000000000"
dq_i = "0000000000000000000000000000000000000000000000000000000000deadbeef000000"
rwds_oe = "________________________________________________________________________"
for i in range(3):
yield
for i in range(len(clk)):
yield dut.pads.dq.i.eq(int(dq_i[2*(i//2):2*(i//2)+2], 16))
self.assertEqual(c2bool(clk[i]), (yield dut.pads.clk))
self.assertEqual(c2bool(cs_n[i]), (yield dut.pads.cs_n))
self.assertEqual(c2bool(dq_oe[i]), (yield dut.pads.dq.oe))
self.assertEqual(int(dq_o[2*(i//2):2*(i//2)+2], 16), (yield dut.pads.dq.o))
self.assertEqual(c2bool(rwds_oe[i]), (yield dut.pads.rwds.oe))
yield
dut = HyperRAM(HyperRamPads())
run_simulation(dut, [fpga_gen(dut), hyperram_gen(dut)])