Merge pull request #1627 from trabucayre/CC_PLL

soc/cores/clock: adding CologneChip CC_PLL

litex/soc/cores/clock/colognechip.py

@@ -0,0 +1,151 @@
+#
+# This file is part of LiteX.
+#
+# Copyright (c) 2023 Gwenhael Goavec-merou<gwenhael.goavec-merou@trabucayre.com>
+# SPDX-License-Identifier: BSD-2-Clause
+
+from migen import *
+from migen.genlib.resetsync import AsyncResetSynchronizer
+
+from litex.gen import *
+
+from litex.soc.cores.clock.common import *
+
+# CologneChip GateMate CC_PLL ---------------------------------------------------------------------
+
+class GateMatePLL(LiteXModule):
+    """
+    CC_PLL generator for CologneChip GateMate FPGAs (UG1001 7.3)
+    Parameters
+    ----------
+    perf_mode: str
+        FPGA operation mode for VDD_PLL (UNDEFINED, LOWPOWER, ECONOMY, SPEED) (default: UNDEFINED)
+    low_jitter: int
+        Low Jitter Mode (0,1) (default: 1)
+    lock_req: int
+        Lock status required before PLL output enable (0,1) (default: 0)
+
+    Attributes
+    ----------
+    reset: Signal in
+    locked: Signal out
+    """
+
+    def __init__(self,
+        perf_mode  = "undefined",
+        low_jitter = 1,
+        lock_req   = 0):
+
+        assert perf_mode.lower() in ["undefined", "lowpower", "economy", "speed"]
+        assert low_jitter in [0, 1]
+        assert lock_req in [0, 1]
+
+        self.logger      = logging.getLogger("CC_PLL")
+        self.reset       = Signal()
+        self.locked      = Signal()
+        self._clkin_freq = None
+        self._clkouts    = {}
+        self._perf_mode  = perf_mode.upper()
+        self._low_jitter = low_jitter
+        self._lock_req   = lock_req
+
+        self._max_freq   = {
+            "undefined" : 250e6,
+            "lowpower"  : 250e6,
+            "economy"   : 312.5e6,
+            "speed"     : 416.75e6
+        }[perf_mode.lower()]
+
+    def register_clkin(self, clkin, freq, usr_clk_ref=False):
+        """
+        Register clkin signal as input PLL input signal
+        Parameters
+        ----------
+        clkin: ClockSignal / Signal
+            input clock signal
+        freq: float
+            input clock frequency (Hz)
+        usr_clk_ref: bool
+            select if clkin is connected to CLK_REF or USR_CLK_REF
+        """
+        self._usr_clk_ref = usr_clk_ref
+        self._clkin = Signal()
+        if isinstance(clkin, (Signal, ClockSignal)):
+            self.comb += self._clkin.eq(clkin)
+        else:
+            raise ValueError
+        self._clkin_freq = freq
+        register_clkin_log(self.logger, clkin, freq)
+
+    def create_clkout(self, cd, freq, phase=0, with_reset=True):
+        """
+        Register cd ClockDomain as PLL output signal
+        Parameters
+        ----------
+        cd: ClockDomain
+            input clock signal
+        freq: float
+            output clock frequency (Hz)
+        phase: int
+            must be 0, 90, 180, 270
+        with_reset: bool
+            drive cd reset
+        """
+        assert phase in [0, 90, 180, 270]
+        assert phase not in self._clkouts
+        assert freq <= self._max_freq
+
+        clkout = Signal()
+        self._clkouts[phase] = (clkout, freq)
+        if with_reset:
+            self.specials += AsyncResetSynchronizer(cd, ~self.locked)
+        self.comb += cd.clk.eq(clkout)
+        create_clkout_log(self.logger, cd.name, freq, 0, phase)
+
+    def do_finalize(self):
+        assert hasattr(self, "_clkin")
+        assert len(self._clkouts) > 0
+
+        # set/unset frequency doubler for CLK180/CLK270
+        clk_doub    = {180:0, 270:0}
+        # extract slowest frequency -> ref
+        clkout_freq = min([f for (_, f) in self._clkouts.values()])
+
+        for phase in [0, 90, 180, 270]:
+            (clk, freq) = self._clkouts.get(phase, (Open(), 0))
+            self._clkouts[phase] = (clk, freq) # force update (add unselected output)
+            if freq != 0:
+                # clk0 and clk90 frequency must be equal to clkout freq
+                if phase in [0, 90]:
+                    assert freq == clkout_freq
+                else:
+                    # clk180 and clk270 must be x1 or x2 clkout frequency
+                    assert freq in [clkout_freq, 2 * clkout_freq]
+                    # when clk180 or clk270 == x2 clkout: CLKxx_DOUB must be set
+                    if freq == 2 * clkout_freq:
+                        clk_doub[phase] = 1
+
+        assert clkout_freq is not None
+
+        freqInMHz  = self._clkin_freq/1e6
+        freqOutMHz = clkout_freq/1e6
+
+        self.specials += Instance("CC_PLL",
+            p_REF_CLK             = freqInMHz,        # reference input in MHz
+            p_OUT_CLK             = freqOutMHz,       # pll output frequency in MHz
+            p_LOW_JITTER          = self._low_jitter, # 0: disable, 1: enable low jitter mode
+            p_PERF_MD             = self._perf_mode,  # FPGA operation mode for VDD_PLL
+            p_LOCK_REQ            = self._lock_req,   # Lock status required before PLL output enable
+            p_CI_FILTER_CONST     = 2,                # optional CI filter constant
+            p_CP_FILTER_CONST     = 4,                # optional CP filter constant
+            i_CLK_REF             = self._clkin if not self._usr_clk_ref else Open(),
+            i_USR_CLK_REF         = self._clkin if self._usr_clk_ref else Open(),
+            i_CLK_FEEDBACK        = 0,
+            i_USR_LOCKED_STDY_RST = self.reset,
+            o_CLK_REF_OUT         = Open(),
+            o_USR_PLL_LOCKED_STDY = Open(),
+            o_USR_PLL_LOCKED      = self.locked,
+            **{f"o_CLK{p}"        : c for (p, (c, _)) in self._clkouts.items()},
+            **{f"p_CLK{p}_DOUB"   : v for (p, v) in clk_doub.items()},
+        )
+