diff --git a/litex/soc/cores/clock/colognechip.py b/litex/soc/cores/clock/colognechip.py new file mode 100644 index 000000000..e4112aa8d --- /dev/null +++ b/litex/soc/cores/clock/colognechip.py @@ -0,0 +1,151 @@ +# +# This file is part of LiteX. +# +# Copyright (c) 2023 Gwenhael Goavec-merou +# 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()}, + ) +