zc706: add CXP_DEMO variant

zc706: add fmc pads
zc706: add constraint to fix comma alignment & setup/hold time issue
zc706: add csr & mem group for cxp

src/gateware/zc706.py

@@ -25,6 +25,8 @@ import analyzer
 import acpki
 import drtio_aux_controller
 import zynq_clocking
+import cxp_4r_fmc
+import cxp
 from config import write_csr_file, write_mem_file, write_rustc_cfg_file
 
 class SMAClkinForward(Module):
@@ -138,7 +140,7 @@ class ZC706(SoCCore):
         platform.add_extension(si5324_fmc33)
         self.comb += platform.request("si5324_33").rst_n.eq(1)
 
-        cdr_clk = Signal()
+        self.cdr_clk = Signal()
         cdr_clk_buf = Signal()
         si5324_out = platform.request("si5324_clkout")
         platform.add_period_constraint(si5324_out.p, 8.0)
@@ -146,11 +148,11 @@ class ZC706(SoCCore):
             Instance("IBUFDS_GTE2",
                 i_CEB=0,
                 i_I=si5324_out.p, i_IB=si5324_out.n,
-                o_O=cdr_clk,
+                o_O=self.cdr_clk,
                 p_CLKCM_CFG="TRUE",
                 p_CLKRCV_TRST="TRUE",
                 p_CLKSWING_CFG=3),
-            Instance("BUFG", i_I=cdr_clk, o_O=cdr_clk_buf)
+            Instance("BUFG", i_I=self.cdr_clk, o_O=cdr_clk_buf)
         ]
         self.config["HAS_SI5324"] = None
         self.config["SI5324_AS_SYNTHESIZER"] = None
@@ -652,6 +654,119 @@ class _NIST_QC2_RTIO:
         self.add_rtio(rtio_channels)
 
 
+class CXP_FMC():
+    """
+    CoaXpress FMC with 4 CXP channel and 1 SMA trigger
+    """
+    def __init__(self):
+        platform = self.platform
+        platform.add_extension(cxp_4r_fmc.fmc_adapter_io)
+        platform.add_extension(leds_fmc33)
+
+        debug_sma = [
+            ("user_sma_clock_33", 0,
+                Subsignal("p_tx", Pins("AD18"), IOStandard("LVCMOS33")),
+                Subsignal("n_rx", Pins("AD19"), IOStandard("LVCMOS33")),
+            ),
+        ]
+
+        pmod1_33 = [
+            ("pmod1_33", 0, Pins("AJ21"), IOStandard("LVCMOS33")),
+            ("pmod1_33", 1, Pins("AK21"), IOStandard("LVCMOS33")),
+            ("pmod1_33", 2, Pins("AB21"), IOStandard("LVCMOS33")),
+            ("pmod1_33", 3, Pins("AB16"), IOStandard("LVCMOS33")),
+            ("pmod1_33", 4, Pins("Y20"), IOStandard("LVCMOS33")),
+            ("pmod1_33", 5, Pins("AA20"), IOStandard("LVCMOS33")),
+            ("pmod1_33", 6, Pins("AC18"), IOStandard("LVCMOS33")),
+            ("pmod1_33", 7, Pins("AC19"), IOStandard("LVCMOS33")),
+        ]
+
+        platform.add_extension(debug_sma)
+        platform.add_extension(pmod1_33)
+        debug_sma_pad = platform.request("user_sma_clock_33") 
+        pmod_pads = [platform.request("pmod1_33", i) for i in range(8)]
+
+        clk_freq = 125e6
+
+        links = 1
+        cxp_downconn_pads = [platform.request("CXP_HS", i) for i in range(links)]
+        cxp_upconn_pads = [platform.request("CXP_LS", i) for i in range(links)]
+
+
+        self.submodules.cxp_phys = cxp_phys = cxp.CXP_PHYS(
+            refclk=self.cdr_clk,
+            upconn_pads=cxp_upconn_pads,
+            downconn_pads=cxp_downconn_pads,
+            sys_clk_freq=clk_freq,
+            debug_sma=debug_sma_pad,
+            pmod_pads = pmod_pads
+        )
+        self.csr_devices.append("cxp_phys")
+
+
+        cxp_csr_group = []
+        cxp_tx_mem_group = []
+        cxp_rx_mem_group = []
+        cxp_loopback_mem_group = []
+        for i, (tx, rx) in enumerate(zip(cxp_phys.upconn.tx_phys, cxp_phys.downconn.rx_phys)):
+            cxp_name = "cxp" + str(i)
+
+            # TODO: cdr = ClockDomainsRenamer({"cxp_gtx_rx": "cxp_gtx_rx" + str(i)})
+            
+            cxp_interface = cxp.CXP_Interface(tx, rx, debug_sma_pad, pmod_pads)
+            setattr(self.submodules, cxp_name, cxp_interface )
+            self.csr_devices.append(cxp_name)
+            cxp_csr_group.append(cxp_name)
+            
+
+            tx_mem_name = "cxp_tx" + str(i) + "_mem"
+            tx_mem_size = cxp_interface.get_tx_mem_size()
+            memory_address = self.axi2csr.register_port(cxp_interface.get_tx_port(), tx_mem_size)
+            self.add_memory_region(tx_mem_name, self.mem_map["csr"] + memory_address, tx_mem_size)
+            cxp_tx_mem_group.append(tx_mem_name)
+
+            rx_mem_name = "cxp_rx" + str(i) + "_mem"
+            rx_mem_size = cxp_interface.get_rx_mem_size()
+            memory_address = self.axi2csr.register_port(cxp_interface.get_rx_port(), rx_mem_size)
+            self.add_memory_region(rx_mem_name, self.mem_map["csr"] + memory_address, rx_mem_size)
+            cxp_rx_mem_group.append(rx_mem_name)
+
+
+            # DEBUG loopback tx memory
+            loopback_mem_name = "cxp_loopback_tx" + str(i) + "_mem"
+            loopback_mem_size = cxp_interface.get_loopback_tx_mem_size()
+            cxp_loopback_mem_group.append(loopback_mem_name)
+            memory_address = self.axi2csr.register_port(cxp_interface.get_loopback_tx_port(), loopback_mem_size)
+            self.add_memory_region(loopback_mem_name, self.mem_map["csr"] + memory_address, loopback_mem_size)
+
+        self.add_memory_group("cxp_tx_mem", cxp_tx_mem_group)
+        self.add_memory_group("cxp_rx_mem", cxp_rx_mem_group)
+        self.add_memory_group("cxp_loopback_mem", cxp_loopback_mem_group)
+        self.add_csr_group("cxp", cxp_csr_group)
+
+        # max freq of cxp_gtx_rx = linerate/internal_datawidth = 12.5Gbps/40 = 312.5MHz
+        # zc706 use speed grade 2 which only support up to 10.3125Gbps (4ns)
+        # pushing to 12.5Gbps (3.2ns) will result in Pulse width violation but setup/hold times are met
+        for rx in cxp_phys.downconn.rx_phys :
+            platform.add_period_constraint(rx.gtx.cd_cxp_gtx_tx.clk, 3.2)
+            platform.add_period_constraint(rx.gtx.cd_cxp_gtx_rx.clk, 3.2)
+            # constraint the CLK path 
+            platform.add_false_path_constraints(self.sys_crg.cd_sys.clk, rx.gtx.cd_cxp_gtx_tx.clk, rx.gtx.cd_cxp_gtx_rx.clk)
+
+        rtio_channels = []
+        # FIXME remove this placeholder RTIO channel
+        # There are too few RTIO channels and cannot be compiled (adr width issue of the lane distributor)
+        # see https://github.com/m-labs/artiq/pull/2158 for similar issue
+        print("USER LED at RTIO channel 0x{:06x}".format(len(rtio_channels)))
+        phy = ttl_simple.Output(self.platform.request("user_led_33", 0))
+        self.submodules += phy
+        rtio_channels.append(rtio.Channel.from_phy(phy))
+        self.config["HAS_RTIO_LOG"] = None
+        rtio_channels.append(rtio.LogChannel())
+
+        self.config["RTIO_LOG_CHANNEL"] = len(rtio_channels)
+        self.add_rtio(rtio_channels)
+
 class NIST_CLOCK(ZC706, _NIST_CLOCK_RTIO):
     def __init__(self, acpki, drtio100mhz):
         ZC706.__init__(self, acpki)
@@ -684,8 +799,13 @@ class NIST_QC2_Satellite(_SatelliteBase, _NIST_QC2_RTIO):
         _SatelliteBase.__init__(self, acpki, drtio100mhz)
         _NIST_QC2_RTIO.__init__(self)
 
+class CXP_Demo(ZC706, CXP_FMC):
+    def __init__(self, acpki, drtio100mhz):
+        ZC706.__init__(self, acpki)
+        CXP_FMC.__init__(self)
+
 VARIANTS = {cls.__name__.lower(): cls for cls in [NIST_CLOCK, NIST_CLOCK_Master, NIST_CLOCK_Satellite,
-                                                  NIST_QC2, NIST_QC2_Master, NIST_QC2_Satellite]}
+                                                  NIST_QC2, NIST_QC2_Master, NIST_QC2_Satellite, CXP_Demo]}
 
 def main():
     parser = argparse.ArgumentParser(