Add PTP clock simulation model

Author: alexforencich

tb/ptp.py

@@ -0,0 +1,127 @@
+"""
+
+Copyright (c) 2015-2019 Alex Forencich
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+"""
+
+from myhdl import *
+
+class PtpClock(object):
+    def __init__(self):
+        self.period_ns = 0x6
+        self.period_fns = 0x6666
+        self.drift_ns = 0x0
+        self.drift_fns = 0x0002
+        self.drift_rate = 5
+
+        self.set_96_l = []
+        self.set_64_l = []
+
+    def set_96(self, ts):
+        self.set_96_l.append(ts)
+
+    def set_64(self, ts):
+        self.set_64_l.append(ts)
+
+    def create_logic(self,
+            clk,
+            rst,
+            ts_96=Signal(intbv(0)[96:]),
+            ts_64=Signal(intbv(0)[64:]),
+            ts_step=Signal(bool(0))
+        ):
+
+        @instance
+        def logic():
+
+            ts_96_s = 0
+            ts_96_ns = 0
+            ts_96_fns = 0
+
+            ts_64_ns = 0
+            ts_64_fns = 0
+
+            drift_cnt = 0
+
+            while True:
+                yield clk.posedge, rst.posedge
+
+                if rst:
+                    ts_96_s = 0
+                    ts_96_ns = 0
+                    ts_96_fns = 0
+                    ts_64_ns = 0
+                    ts_64_fns = 0
+                    drift_cnt = 0
+                    ts_96.next = 0
+                    ts_64.next = 0
+                else:
+                    ts_step.next = 0
+
+                    t = ((ts_96_ns << 16) + ts_96_fns) + ((self.period_ns << 16) + self.period_fns)
+
+                    if drift_cnt > 0:
+                        t += (self.drift_ns << 16) + self.drift_fns
+                        ts_step.next = 1
+
+                    if t > (1000000000<<16):
+                        ts_96_s += 1
+                        t -= (1000000000<<16)
+
+                    ts_96_fns = t & 0xffff
+                    ts_96_ns = t >> 16
+
+                    if self.set_96_l:
+                        ts = self.set_96_l.pop(0)
+
+                        ts_96_s = ts >> 48
+                        ts_96_ns = (ts >> 16) & 0x3fffffff
+                        ts_96_fns = ts & 0xffff
+
+                        ts_step.next = 1
+
+                    ts_96.next = (ts_96_s << 48) | (ts_96_ns << 16) | (ts_96_fns)
+
+                    t = ((ts_64_ns << 16) + ts_64_fns) + ((self.period_ns << 16) + self.period_fns)
+
+                    if drift_cnt > 0:
+                        t += ((self.drift_ns << 16) + self.drift_fns)
+                        ts_step.next = 1
+
+                    ts_64_fns = t & 0xffff
+                    ts_64_ns = t >> 16
+
+                    if self.set_64_l:
+                        ts = self.set_64_l.pop(0)
+
+                        ts_64_ns = ts >> 16
+                        ts_64_fns = ts & 0xffff
+
+                        ts_step.next = 1
+
+                    ts_64.next = (ts_64_ns << 16) | ts_64_fns
+
+                    if drift_cnt > 0:
+                        drift_cnt -= 1
+                    else:
+                        drift_cnt = self.drift_rate-1
+
+        return instances()