Gateware: WRPLL

ddmtd: add DDMTD and deglitcher
wrpll: add helper clockdomain
wrpll: add frequency counter
wrpll: add skewtester
wrpll: add gtx & main tag collection
wrpll: add gtx & main tag eventmanager for shared peripheral interrupt
wrpll: add SMA frequency multiplier to generate 125Mhz refclk
si549: add i2c and adpll programmer

src/gateware/ddmtd.py

@@ -0,0 +1,67 @@
+from migen import *
+from migen.genlib.cdc import PulseSynchronizer, MultiReg
+from misoc.interconnect.csr import *
+
+
+class DDMTDSampler(Module):
+    def __init__(self, cd_ref, main_clk_se):
+        self.ref_beating = Signal()
+        self.main_beating = Signal()
+
+        # # #
+
+        ref_beating_FF = Signal()
+        main_beating_FF = Signal()
+        self.specials += [
+            # Two back to back FFs are used to prevent metastability
+            Instance("FD", i_C=ClockSignal("helper"),
+                     i_D=cd_ref.clk, o_Q=ref_beating_FF),
+            Instance("FD", i_C=ClockSignal("helper"),
+                     i_D=ref_beating_FF, o_Q=self.ref_beating),
+            Instance("FD", i_C=ClockSignal("helper"),
+                     i_D=main_clk_se, o_Q=main_beating_FF),
+            Instance("FD", i_C=ClockSignal("helper"),
+                     i_D=main_beating_FF, o_Q=self.main_beating)
+        ]
+
+
+class DDMTDDeglitcherFirstEdge(Module):
+    def __init__(self, input_signal, blind_period=400):
+        self.detect = Signal()
+        rising = Signal()
+        input_signal_r = Signal()
+
+        # # #
+
+        self.sync.helper += [
+            input_signal_r.eq(input_signal),
+            rising.eq(input_signal & ~input_signal_r)
+        ]
+
+        blind_counter = Signal(max=blind_period)
+        self.sync.helper += [
+            If(blind_counter != 0, blind_counter.eq(blind_counter - 1)),
+            If(input_signal_r, blind_counter.eq(blind_period - 1)),
+            self.detect.eq(rising & (blind_counter == 0))
+        ]
+
+
+class DDMTD(Module):
+    def __init__(self, counter, input_signal):
+
+        # in helper clock domain
+        self.h_tag = Signal(len(counter))
+        self.h_tag_update = Signal()
+
+        # # #
+
+        deglitcher = DDMTDDeglitcherFirstEdge(input_signal)
+        self.submodules += deglitcher
+
+        self.sync.helper += [
+            self.h_tag_update.eq(0),
+            If(deglitcher.detect,
+                self.h_tag_update.eq(1),
+                self.h_tag.eq(counter)
+               )
+        ]

src/gateware/si549.py

@@ -0,0 +1,277 @@
+from migen import *
+from migen.genlib.fsm import *
+
+from misoc.interconnect.csr import *
+
+
+class I2CClockGen(Module):
+    def __init__(self, width):
+        self.load = Signal(width)
+        self.clk2x = Signal()
+
+        cnt = Signal.like(self.load)
+        self.comb += [
+            self.clk2x.eq(cnt == 0),
+        ]
+        self.sync += [
+            If(self.clk2x,
+                cnt.eq(self.load),
+            ).Else(
+                cnt.eq(cnt - 1),
+            )
+        ]
+
+
+class I2CMasterMachine(Module):
+    def __init__(self, clock_width):
+        self.scl = Signal(reset=1)
+        self.sda_o = Signal(reset=1)
+        self.sda_i = Signal()
+
+        self.submodules.cg = CEInserter()(I2CClockGen(clock_width))
+        self.start = Signal()
+        self.stop = Signal()
+        self.write = Signal()
+        self.ack = Signal()
+        self.data = Signal(8)
+        self.ready = Signal()
+
+        # # #
+
+        bits = Signal(4)
+        data = Signal(8)
+
+        fsm = CEInserter()(FSM("IDLE"))
+        self.submodules += fsm
+
+        fsm.act("IDLE",
+            self.ready.eq(1),
+            If(self.start,
+                NextState("START0"),
+            ).Elif(self.stop,
+                NextState("STOP0"),
+            ).Elif(self.write,
+                NextValue(bits, 8),
+                NextValue(data, self.data),
+                NextState("WRITE0")
+            )
+        )
+
+        fsm.act("START0",
+            NextValue(self.scl, 1),
+            NextState("START1")
+        )
+        fsm.act("START1",
+            NextValue(self.sda_o, 0),
+            NextState("IDLE")
+        )
+
+        fsm.act("STOP0",
+            NextValue(self.scl, 0),
+            NextState("STOP1")
+        )
+        fsm.act("STOP1",
+            NextValue(self.sda_o, 0),
+            NextState("STOP2")
+        )
+        fsm.act("STOP2",
+            NextValue(self.scl, 1), 
+            NextState("STOP3")
+        )
+        fsm.act("STOP3",
+            NextValue(self.sda_o, 1),
+            NextState("IDLE")
+        )
+
+        fsm.act("WRITE0",
+            NextValue(self.scl, 0),
+            NextState("WRITE1")
+        )
+        fsm.act("WRITE1",
+            If(bits == 0,
+                NextValue(self.sda_o, 1),
+                NextState("READACK0"),
+            ).Else(
+                NextValue(self.sda_o, data[7]),
+                NextState("WRITE2"),
+            )
+        )
+        fsm.act("WRITE2",
+            NextValue(self.scl, 1),
+            NextValue(data[1:], data[:-1]),
+            NextValue(bits, bits - 1),
+            NextState("WRITE0"),
+        )
+        fsm.act("READACK0",
+            NextValue(self.scl, 1),
+            NextState("READACK1"),
+        )
+        fsm.act("READACK1",
+            NextValue(self.ack, ~self.sda_i),
+            NextState("IDLE")
+        )
+
+        run = Signal()
+        idle = Signal()
+        self.comb += [
+            run.eq((self.start | self.stop | self.write) & self.ready),
+            idle.eq(~run & fsm.ongoing("IDLE")),
+            self.cg.ce.eq(~idle),
+            fsm.ce.eq(run | self.cg.clk2x),
+        ]
+
+
+class ADPLLProgrammer(Module):
+    def __init__(self):
+        self.i2c_divider = Signal(16)
+        self.i2c_address = Signal(7)
+
+        self.adpll = Signal(24)
+        self.stb = Signal()
+        self.busy = Signal()
+        self.nack = Signal()
+
+        self.scl = Signal()
+        self.sda_i = Signal()
+        self.sda_o = Signal()
+
+        # # #
+
+        master = I2CMasterMachine(16)
+        self.submodules += master
+
+        self.comb += [
+            master.cg.load.eq(self.i2c_divider),
+            self.scl.eq(master.scl),
+            master.sda_i.eq(self.sda_i),
+            self.sda_o.eq(master.sda_o)
+        ]
+
+        fsm = FSM()
+        self.submodules += fsm
+
+        fsm.act("IDLE",
+            If(self.stb,
+                NextValue(self.nack, 0),
+                NextState("START")
+            )
+        )
+        fsm.act("START",
+            master.start.eq(1),
+            If(master.ready, NextState("DEVADDRESS"))
+        )
+        fsm.act("DEVADDRESS",
+            master.data.eq(self.i2c_address << 1),
+            master.write.eq(1),
+            If(master.ready, NextState("REGADRESS"))
+        )
+        fsm.act("REGADRESS",
+            master.data.eq(231),
+            master.write.eq(1),
+            If(master.ready,
+                If(master.ack,
+                    NextState("DATA0")
+                ).Else(
+                    NextValue(self.nack, 1),
+                    NextState("STOP")
+                )
+            )
+        )
+        fsm.act("DATA0",
+            master.data.eq(self.adpll[0:8]),
+            master.write.eq(1),
+            If(master.ready,
+                If(master.ack,
+                    NextState("DATA1")
+                ).Else(
+                    NextValue(self.nack, 1),
+                    NextState("STOP")
+                )
+            )
+        )
+        fsm.act("DATA1",
+            master.data.eq(self.adpll[8:16]),
+            master.write.eq(1),
+            If(master.ready,
+                If(master.ack,
+                    NextState("DATA2")
+                ).Else(
+                    NextValue(self.nack, 1),
+                    NextState("STOP")
+                )
+            )
+        )
+        fsm.act("DATA2",
+            master.data.eq(self.adpll[16:24]),
+            master.write.eq(1),
+            If(master.ready,
+                If(~master.ack, NextValue(self.nack, 1)),
+                NextState("STOP")
+            )
+        )
+        fsm.act("STOP",
+            master.stop.eq(1),
+            If(master.ready,
+                If(~master.ack, NextValue(self.nack, 1)),
+                NextState("IDLE")
+            )
+        )
+
+        self.comb += self.busy.eq(~fsm.ongoing("IDLE"))
+
+
+class Si549(Module, AutoCSR):
+    def __init__(self, pads):
+        self.i2c_divider = CSRStorage(16, reset=75)
+        self.i2c_address = CSRStorage(7)
+
+        self.adpll = CSRStorage(24)
+        self.adpll_stb = CSR()
+        self.adpll_busy = CSRStatus()
+        self.nack = CSRStatus()
+
+        self.bitbang_enable = CSRStorage()
+
+        self.sda_oe = CSRStorage()
+        self.sda_out = CSRStorage()
+        self.sda_in = CSRStatus()
+        self.scl_oe = CSRStorage()
+        self.scl_out = CSRStorage()
+
+        # # #
+
+        self.submodules.programmer = ADPLLProgrammer()
+
+        self.sync += self.programmer.stb.eq(self.adpll_stb.re)
+
+        self.comb += [
+            self.programmer.i2c_divider.eq(self.i2c_divider.storage),
+            self.programmer.i2c_address.eq(self.i2c_address.storage),
+            self.programmer.adpll.eq(self.adpll.storage),
+            self.adpll_busy.status.eq(self.programmer.busy),
+            self.nack.status.eq(self.programmer.nack)
+        ]
+
+        # I2C with bitbang/gateware mode select
+        sda_t = TSTriple(1)
+        scl_t = TSTriple(1)
+        self.specials += [
+            sda_t.get_tristate(pads.sda),
+            scl_t.get_tristate(pads.scl)
+        ]
+
+        self.comb += [
+            If(self.bitbang_enable.storage,
+                sda_t.oe.eq(self.sda_oe.storage),
+                sda_t.o.eq(self.sda_out.storage),
+                self.sda_in.status.eq(sda_t.i),
+                scl_t.oe.eq(self.scl_oe.storage),
+                scl_t.o.eq(self.scl_out.storage)
+            ).Else(
+                sda_t.oe.eq(~self.programmer.sda_o),
+                sda_t.o.eq(0),
+                self.programmer.sda_i.eq(sda_t.i),
+                scl_t.oe.eq(~self.programmer.scl),
+                scl_t.o.eq(0),
+            )
+        ]

src/gateware/wrpll.py

@@ -0,0 +1,237 @@
+from migen import *
+from migen.genlib.cdc import MultiReg, AsyncResetSynchronizer, PulseSynchronizer
+from misoc.interconnect.csr import *
+from misoc.interconnect.csr_eventmanager import *
+
+from ddmtd import DDMTDSampler, DDMTD
+from si549 import Si549
+
+class FrequencyCounter(Module, AutoCSR):
+    def __init__(self, domains, counter_width=24):
+        self.update = CSR()
+        self.busy = CSRStatus()
+
+        counter_reset = Signal()
+        counter_stb = Signal()
+        timer = Signal(counter_width)
+
+        # # #
+
+        fsm = FSM()
+        self.submodules += fsm
+
+        fsm.act("IDLE",
+            counter_reset.eq(1),
+            If(self.update.re,
+                NextValue(timer, 2**counter_width - 1),
+                NextState("COUNTING")
+            )
+        )
+        fsm.act("COUNTING",
+            self.busy.status.eq(1),
+            If(timer != 0,
+                NextValue(timer, timer - 1)
+            ).Else( 
+                counter_stb.eq(1),
+                NextState("IDLE")
+            )
+        )
+
+        for domain in domains:
+            name = "counter_" + domain
+            counter_csr = CSRStatus(counter_width, name=name)
+            setattr(self, name, counter_csr)
+
+            divider = Signal(2)
+            divided = Signal()
+            divided_sys = Signal()
+            divided_sys_r = Signal()
+            divided_tick = Signal()
+            counter = Signal(counter_width)
+
+            # # #
+
+            sync_domain = getattr(self.sync, domain)
+            sync_domain +=[
+                divider.eq(divider + 1),
+                divided.eq(divider[-1])
+            ]
+            self.specials += MultiReg(divided, divided_sys)
+            self.sync += divided_sys_r.eq(divided_sys)
+            self.comb += divided_tick.eq(divided_sys & ~divided_sys_r)
+
+            self.sync += [
+                If(counter_stb, counter_csr.status.eq(counter)),
+                If(divided_tick, counter.eq(counter + 1)),
+                If(counter_reset, counter.eq(0))
+            ]
+
+class SkewTester(Module, AutoCSR):
+    def __init__(self, rx_synchronizer):
+        self.error = CSR()
+
+        # # #
+        
+        # The RX synchronizer is tested for setup/hold violations by feeding it a
+        # toggling pattern and checking that the same toggling pattern comes out.
+        toggle_in = Signal()
+        self.sync.rtio_rx0 += toggle_in.eq(~toggle_in)
+        toggle_out = rx_synchronizer.resync(toggle_in)
+
+        toggle_out_expected = Signal()
+        self.sync += toggle_out_expected.eq(~toggle_out)
+
+        error = Signal()
+        self.sync += [
+            If(toggle_out != toggle_out_expected, error.eq(1)),
+            If(self.error.re, error.eq(0))
+        ]
+        self.specials += MultiReg(error, self.error.w)
+
+
+class WRPLL(Module, AutoCSR):
+    def __init__(self, platform, cd_ref, main_clk_se, COUNTER_BIT=32):
+        self.helper_reset = CSRStorage(reset=1)
+        self.ref_tag = CSRStatus(COUNTER_BIT)
+        self.main_tag = CSRStatus(COUNTER_BIT)
+
+        ddmtd_counter = Signal(COUNTER_BIT)
+
+        ref_tag_sys = Signal(COUNTER_BIT)
+        main_tag_sys = Signal(COUNTER_BIT)
+        ref_tag_stb_sys = Signal()
+        main_tag_stb_sys = Signal()
+
+        # # #
+
+        self.submodules.main_dcxo = Si549(platform.request("ddmtd_main_dcxo_i2c"))
+        self.submodules.helper_dcxo = Si549(platform.request("ddmtd_helper_dcxo_i2c"))
+
+        helper_dcxo_pads = platform.request("ddmtd_helper_clk")
+        self.clock_domains.cd_helper = ClockDomain()
+        self.specials += [
+            Instance("IBUFGDS",
+                     i_I=helper_dcxo_pads.p, i_IB=helper_dcxo_pads.n,
+                     o_O=self.cd_helper.clk),
+            AsyncResetSynchronizer(self.cd_helper, self.helper_reset.storage)
+        ]
+
+        self.submodules.frequency_counter = FrequencyCounter(["sys", cd_ref.name])
+
+        self.submodules.ddmtd_sampler = DDMTDSampler(cd_ref, main_clk_se)
+
+        self.sync.helper += ddmtd_counter.eq(ddmtd_counter + 1)
+        self.submodules.ddmtd_ref = DDMTD(ddmtd_counter, self.ddmtd_sampler.ref_beating)
+        self.submodules.ddmtd_main = DDMTD(ddmtd_counter, self.ddmtd_sampler.main_beating)
+
+        # DDMTD tags collection
+
+        self.specials += [
+            MultiReg(self.ddmtd_ref.h_tag, ref_tag_sys),
+            MultiReg(self.ddmtd_main.h_tag, main_tag_sys)
+        ]
+
+        ref_tag_stb_ps = PulseSynchronizer("helper", "sys")
+        main_tag_stb_ps = PulseSynchronizer("helper", "sys")
+        self.submodules += [
+            ref_tag_stb_ps,
+            main_tag_stb_ps
+        ]
+        self.sync.helper += [
+            ref_tag_stb_ps.i.eq(self.ddmtd_ref.h_tag_update),
+            main_tag_stb_ps.i.eq(self.ddmtd_main.h_tag_update)
+        ]
+        self.sync += [
+            ref_tag_stb_sys.eq(ref_tag_stb_ps.o),
+            main_tag_stb_sys.eq(main_tag_stb_ps.o)
+        ]
+
+        self.sync += [
+            If(ref_tag_stb_sys,
+                self.ref_tag.status.eq(ref_tag_sys),
+            ),
+            If(main_tag_stb_sys,
+                self.main_tag.status.eq(main_tag_sys)
+            )
+        ]
+
+        # EventMangers for firmware interrupt
+
+        self.submodules.ref_tag_ev = EventManager()
+        self.ref_tag_ev.stb = EventSourcePulse()
+        self.ref_tag_ev.finalize()
+
+        self.submodules.main_tag_ev = EventManager()
+        self.main_tag_ev.stb = EventSourcePulse()
+        self.main_tag_ev.finalize()
+
+        self.sync += [
+            self.ref_tag_ev.stb.trigger.eq(ref_tag_stb_sys),
+            self.main_tag_ev.stb.trigger.eq(main_tag_stb_sys)
+        ]
+
+        self.submodules.ev = SharedIRQ(self.ref_tag_ev, self.main_tag_ev)
+
+
+class SMAFrequencyMultiplier(Module, AutoCSR):
+    def __init__(self, sma_clkin):
+        sma_clkin_se = Signal()
+        mmcm_locked = Signal()
+        mmcm_fb_clk = Signal()
+        ref_clk = Signal()
+        self.clock_domains.cd_ref = ClockDomain()
+        self.refclk_reset = CSRStorage(reset=1)
+
+        self.mmcm_bypass = CSRStorage()
+        self.mmcm_locked = CSRStatus()
+        self.mmcm_reset = CSRStorage(reset=1)
+
+        self.mmcm_daddr = CSRStorage(7)
+        self.mmcm_din = CSRStorage(16)
+        self.mmcm_dwen = CSRStorage()
+        self.mmcm_den = CSRStorage()
+        self.mmcm_dclk = CSRStorage()
+        self.mmcm_dout = CSRStatus(16)
+        self.mmcm_dready = CSRStatus()
+
+        # # #
+
+        self.specials += [
+            Instance("IBUFDS",
+                i_I=sma_clkin.p, i_IB=sma_clkin.n,
+                o_O=sma_clkin_se),
+            # MMCME2 is capable to accept 10MHz input while PLLE2 only support down to 19MHz input (DS191)
+            # The MMCME2 can be reconfiged during runtime using the Dynamic Reconfiguration Ports
+            Instance("MMCME2_ADV",
+                p_BANDWIDTH="LOW",  # lower jitter
+                o_LOCKED=self.mmcm_locked.status,
+                i_RST=self.mmcm_reset.storage,
+                
+                p_CLKIN1_PERIOD=8, # ns
+                i_CLKIN1=sma_clkin_se,
+                i_CLKINSEL=1,  # 1=CLKIN1 0=CLKIN2
+
+                # VCO @ 1.25GHz 
+                p_CLKFBOUT_MULT_F=10, p_DIVCLK_DIVIDE=1,
+                i_CLKFBIN=mmcm_fb_clk, o_CLKFBOUT=mmcm_fb_clk, 
+
+                # 125MHz for WRPLL
+                p_CLKOUT0_DIVIDE_F=10, p_CLKOUT0_PHASE=0.0, o_CLKOUT0=ref_clk,
+
+                # Dynamic Reconfiguration Ports
+                i_DADDR = self.mmcm_daddr.storage,
+                i_DI = self.mmcm_din.storage,
+                i_DWE = self.mmcm_dwen.storage,
+                i_DEN = self.mmcm_den.storage,
+                i_DCLK = self.mmcm_dclk.storage,
+                o_DO = self.mmcm_dout.status,
+                o_DRDY = self.mmcm_dready.status
+            ),
+            Instance("BUFGMUX",
+                i_I0=ref_clk,
+                i_I1=sma_clkin_se,
+                i_S=self.mmcm_bypass.storage,
+                o_O=self.cd_ref.clk
+            ),
+            AsyncResetSynchronizer(self.cd_ref, self.refclk_reset.storage),
+        ]