From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Thu, 10 Feb 2022 12:36:33 +0000 (+0000)
Subject: add crg.py
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=19cee64accf72bf0c09853cf2ce980dc4f7a0335;p=ls2.git

add crg.py
---

diff --git a/examples/crg.py b/examples/crg.py
new file mode 100644
index 0000000..f5d35d3
--- /dev/null
+++ b/examples/crg.py
@@ -0,0 +1,134 @@
+# This file is Copyright (c) 2020 LambdaConcept <contact@lambdaconcept.com>
+
+from nmigen import *
+
+__ALL__ = ["ECPIX5CRG"]
+
+class PLL(Elaboratable):
+    def __init__(self, clkin, clksel=Signal(shape=2, reset=2), clkout1=Signal(), clkout2=Signal(), clkout3=Signal(), clkout4=Signal(), lock=Signal(), CLKI_DIV=1, CLKFB_DIV=2, CLK1_DIV=3, CLK2_DIV=24):
+        self.clkin = clkin
+        self.clkout1 = clkout1
+        self.clkout2 = clkout2
+        self.clkout3 = clkout3
+        self.clkout4 = clkout4
+        self.clksel = clksel
+        self.lock = lock
+        self.CLKI_DIV = CLKI_DIV
+        self.CLKFB_DIV = CLKFB_DIV
+        self.CLKOP_DIV = CLK1_DIV
+        self.CLKOS_DIV = CLK2_DIV
+        self.ports = [
+            self.clkin,
+            self.clkout1,
+            self.clkout2,
+            self.clkout3,
+            self.clkout4,
+            self.clksel,
+            self.lock,
+        ]
+
+    def elaborate(self, platform):
+        clkfb = Signal()
+        pll = Instance("EHXPLLL",
+                       p_OUTDIVIDER_MUXA='DIVA',
+                       p_OUTDIVIDER_MUXB='DIVB',
+                       p_CLKOP_ENABLE='ENABLED',
+                       p_CLKOS_ENABLE='ENABLED',
+                       p_CLKOS2_ENABLE='DISABLED',
+                       p_CLKOS3_ENABLE='DISABLED',
+                       p_CLKOP_DIV=self.CLKOP_DIV,
+                       p_CLKOS_DIV=self.CLKOS_DIV,
+                       p_CLKFB_DIV=self.CLKFB_DIV,
+                       p_CLKI_DIV=self.CLKI_DIV,
+                       p_FEEDBK_PATH='INT_OP',
+                       p_CLKOP_TRIM_POL="FALLING",
+                       p_CLKOP_TRIM_DELAY=0,
+                       p_CLKOS_TRIM_POL="FALLING",
+                       p_CLKOS_TRIM_DELAY=0,
+                       i_CLKI=self.clkin,
+                       i_RST=0,
+                       i_STDBY=0,
+                       i_PHASESEL0=0,
+                       i_PHASESEL1=0,
+                       i_PHASEDIR=0,
+                       i_PHASESTEP=0,
+                       i_PHASELOADREG=0,
+                       i_PLLWAKESYNC=0,
+                       i_ENCLKOP=1,
+                       i_ENCLKOS=1,
+                       i_ENCLKOS2=0,
+                       i_ENCLKOS3=0,
+                       o_CLKOP=self.clkout1,
+                       o_CLKOS=self.clkout2,
+                       o_CLKOS2=self.clkout3,
+                       o_CLKOS3=self.clkout4,
+                       o_LOCK=self.lock,
+                       )
+        m = Module()
+        m.submodules += pll
+        return m
+
+
+class ECPIX5CRG(Elaboratable):
+    def __init__(self):
+        ...
+
+    def elaborate(self, platform):
+        m = Module()
+
+        # Get 100Mhz from oscillator
+        clk100 = platform.request("clk100")
+        cd_rawclk = ClockDomain("rawclk", local=True, reset_less=True)
+        m.d.comb += cd_rawclk.clk.eq(clk100)
+        m.domains += cd_rawclk
+
+        # Reset
+        reset = platform.request(platform.default_rst).i
+        gsr0 = Signal()
+        gsr1 = Signal()
+
+        m.submodules += [
+            Instance("FD1S3AX", p_GSR="DISABLED", i_CK=ClockSignal("rawclk"), i_D=~reset, o_Q=gsr0),
+            Instance("FD1S3AX", p_GSR="DISABLED", i_CK=ClockSignal("rawclk"), i_D=gsr0,   o_Q=gsr1),
+            Instance("SGSR", i_CLK=ClockSignal("rawclk"), i_GSR=gsr1),
+        ]
+
+        # Power-on delay (655us)
+        podcnt = Signal(16, reset=2**16-1)
+        pod_done = Signal()
+        with m.If(podcnt != 0):
+            m.d.rawclk += podcnt.eq(podcnt-1)
+        m.d.rawclk += pod_done.eq(podcnt == 0)
+
+        # Generating sync2x (200Mhz) and init (25Mhz) from clk100
+        cd_sync2x = ClockDomain("sync2x", local=False)
+        cd_sync2x_unbuf = ClockDomain("sync2x_unbuf", local=False, reset_less=True)
+        cd_init = ClockDomain("init", local=False)
+        cd_sync = ClockDomain("sync", local=False)
+        cd_dramsync = ClockDomain("dramsync", local=False)
+        m.submodules.pll = pll = PLL(ClockSignal("rawclk"), CLKI_DIV=1, CLKFB_DIV=2, CLK1_DIV=3, CLK2_DIV=24,
+            clkout1=ClockSignal("sync2x_unbuf"), clkout2=ClockSignal("init"))
+        m.submodules += Instance("ECLKSYNCB",
+                i_ECLKI = ClockSignal("sync2x_unbuf"),
+                i_STOP  = 0,
+                o_ECLKO = ClockSignal("sync2x"))
+        m.domains += cd_sync2x_unbuf
+        m.domains += cd_sync2x
+        m.domains += cd_init
+        m.domains += cd_sync
+        m.domains += cd_dramsync
+        m.d.comb += ResetSignal("init").eq(~pll.lock|~pod_done)
+        m.d.comb += ResetSignal("sync").eq(~pll.lock|~pod_done)
+        m.d.comb += ResetSignal("dramsync").eq(~pll.lock|~pod_done)
+
+        # # Generating sync (100Mhz) from sync2x
+        
+        m.submodules += Instance("CLKDIVF",
+            p_DIV="2.0",
+            i_ALIGNWD=0,
+            i_CLKI=ClockSignal("sync2x"),
+            i_RST=0,
+            o_CDIVX=ClockSignal("sync"))
+        m.d.comb += ClockSignal("dramsync").eq(ClockSignal("sync"))
+
+        return m