Improve PTP model resolution by using Decimal types and wider internal fns accumulators

Signed-off-by: Alex Forencich <alex@alexforencich.com>
This commit is contained in:
Alex Forencich
2023-11-07 01:28:25 -08:00
parent c44f928bea
commit 7d8d214b57
4 changed files with 219 additions and 167 deletions

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@@ -603,6 +603,10 @@ To use this module, import it and connect it to the DUT:
Once the clock is instantiated, it will generate a continuous stream of monotonically increasing PTP timestamps on every clock edge. Once the clock is instantiated, it will generate a continuous stream of monotonically increasing PTP timestamps on every clock edge.
Internally, the `PtpClock` module uses 32-bit fractional ns fields for higher frequency resolution. Only the upper 16 bits are returned in the timestamps, but the full fns value can be accessed with the _ts_tod_fns_ and _ts_rel_fns_ attributes.
All APIs that handle fractional values use the `Decimal` type for maximum precision, as the combination of timestamp range and resolution is usually too much for normal floating point numbers to handle without significant loss of precision.
#### Signals #### Signals
* `ts_tod`: 96-bit time-of-day timestamp (48 bit seconds, 32 bit ns, 16 bit fractional ns) * `ts_tod`: 96-bit time-of-day timestamp (48 bit seconds, 32 bit ns, 16 bit fractional ns)
@@ -633,24 +637,26 @@ Once the clock is instantiated, it will generate a continuous stream of monotoni
* `set_period(ns, fns)`: set clock period from separate fields * `set_period(ns, fns)`: set clock period from separate fields
* `set_drift(num, denom)`: set clock drift from separate fields * `set_drift(num, denom)`: set clock drift from separate fields
* `set_period_ns(t)`: set clock period in ns (float) * `set_period_ns(t)`: set clock period and drift in ns (Decimal)
* `get_period_ns()`: return current clock period in ns (float) * `get_period_ns()`: return current clock period in ns (Decimal)
* `set_ts_tod(ts_s, ts_ns, ts_fns)`: set 96-bit ToD timestamp from separate fields * `set_ts_tod(ts_s, ts_ns, ts_fns)`: set 96-bit ToD timestamp from separate fields
* `set_ts_tod_96(ts)`: set 96-bit ToD timestamp from integer * `set_ts_tod_96(ts)`: set 96-bit ToD timestamp from integer
* `set_ts_tod_ns(t)`: set 96-bit ToD timestamp from ns (float) * `set_ts_tod_ns(t)`: set 96-bit ToD timestamp from ns (Decimal)
* `set_ts_tod_s(t)`: set 96-bit ToD timestamp from seconds (float) * `set_ts_tod_s(t)`: set 96-bit ToD timestamp from seconds (Decimal)
* `set_ts_tod_sim_time()`: set 96-bit ToD timestamp from sim time
* `get_ts_tod()`: return current 96-bit ToD timestamp as separate fields * `get_ts_tod()`: return current 96-bit ToD timestamp as separate fields
* `get_ts_tod_96()`: return current 96-bit ToD timestamp as an integer * `get_ts_tod_96()`: return current 96-bit ToD timestamp as an integer
* `get_ts_tod_ns()`: return current 96-bit ToD timestamp in ns (float) * `get_ts_tod_ns()`: return current 96-bit ToD timestamp in ns (Decimal)
* `get_ts_tod_s()`: return current 96-bit ToD timestamp in seconds (float) * `get_ts_tod_s()`: return current 96-bit ToD timestamp in seconds (Decimal)
* `set_ts_rel(ts_ns, ts_fns)`: set 64-bit relative timestamp from separate fields * `set_ts_rel(ts_ns, ts_fns)`: set 64-bit relative timestamp from separate fields
* `set_ts_rel_64(ts)`: set 64-bit relative timestamp from integer * `set_ts_rel_64(ts)`: set 64-bit relative timestamp from integer
* `set_ts_rel_ns(t)`: set 64-bit relative timestamp from ns (float) * `set_ts_rel_ns(t)`: set 64-bit relative timestamp from ns (Decimal)
* `set_ts_rel_s(t)`: set 64-bit relative timestamp from seconds (float) * `set_ts_rel_s(t)`: set 64-bit relative timestamp from seconds (Decimal)
* `set_ts_rel_sim_time()`: set 64-bit relative timestamp from sim time
* `get_ts_rel()`: return current 64-bit relative timestamp as separate fields * `get_ts_rel()`: return current 64-bit relative timestamp as separate fields
* `get_ts_rel_64()`: return current 64-bit relative timestamp as an integer * `get_ts_rel_64()`: return current 64-bit relative timestamp as an integer
* `get_ts_rel_ns()`: return current 64-bit relative timestamp in ns (float) * `get_ts_rel_ns()`: return current 64-bit relative timestamp in ns (Decimal)
* `get_ts_rel_s()`: return current 64-bit relative timestamp in seconds (float) * `get_ts_rel_s()`: return current 64-bit relative timestamp in seconds (Decimal)
### PTP clock (sim time) ### PTP clock (sim time)
@@ -669,6 +675,8 @@ To use this module, import it and connect it to the DUT:
Once the clock is instantiated, it will generate a continuous stream of monotonically increasing PTP timestamps on every clock edge. Once the clock is instantiated, it will generate a continuous stream of monotonically increasing PTP timestamps on every clock edge.
All APIs that handle fractional values use the `Decimal` type for maximum precision, as the combination of timestamp range and resolution is usually too much for normal floating point numbers to handle without significant loss of precision.
#### Signals #### Signals
* `ts_tod`: 96-bit time-of-day timestamp (48 bit seconds, 32 bit ns, 16 bit fractional ns) * `ts_tod`: 96-bit time-of-day timestamp (48 bit seconds, 32 bit ns, 16 bit fractional ns)
@@ -694,9 +702,9 @@ Once the clock is instantiated, it will generate a continuous stream of monotoni
* `get_ts_tod()`: return current 96-bit ToD timestamp as separate fields * `get_ts_tod()`: return current 96-bit ToD timestamp as separate fields
* `get_ts_tod_96()`: return current 96-bit ToD timestamp as an integer * `get_ts_tod_96()`: return current 96-bit ToD timestamp as an integer
* `get_ts_tod_ns()`: return current 96-bit ToD timestamp in ns (float) * `get_ts_tod_ns()`: return current 96-bit ToD timestamp in ns (Decimal)
* `get_ts_tod_s()`: return current 96-bit ToD timestamp in seconds (float) * `get_ts_tod_s()`: return current 96-bit ToD timestamp in seconds (Decimal)
* `get_ts_rel()`: return current 64-bit relative timestamp as separate fields * `get_ts_rel()`: return current 64-bit relative timestamp as separate fields
* `get_ts_rel_96()`: return current 64-bit relative timestamp as an integer * `get_ts_rel_96()`: return current 64-bit relative timestamp as an integer
* `get_ts_rel_ns()`: return current 64-bit relative timestamp in ns (float) * `get_ts_rel_ns()`: return current 64-bit relative timestamp in ns (Decimal)
* `get_ts_rel_s()`: return current 64-bit relative timestamp in seconds (float) * `get_ts_rel_s()`: return current 64-bit relative timestamp in seconds (Decimal)

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@@ -23,7 +23,7 @@ THE SOFTWARE.
""" """
import logging import logging
import math from decimal import Decimal, Context
from fractions import Fraction from fractions import Fraction
import cocotb import cocotb
@@ -56,13 +56,6 @@ class PtpClock(Reset):
self.clock = clock self.clock = clock
self.reset = reset self.reset = reset
self.period_ns = 0
self.period_fns = 0
self.drift_num = 0
self.drift_denom = 0
self.drift_cnt = 0
self.set_period_ns(period_ns)
self.log.info("PTP clock") self.log.info("PTP clock")
self.log.info("cocotbext-eth version %s", __version__) self.log.info("cocotbext-eth version %s", __version__)
self.log.info("Copyright (c) 2020 Alex Forencich") self.log.info("Copyright (c) 2020 Alex Forencich")
@@ -70,6 +63,15 @@ class PtpClock(Reset):
super().__init__(*args, **kwargs) super().__init__(*args, **kwargs)
self.ctx = Context(prec=60)
self.period_ns = 0
self.period_fns = 0
self.drift_num = 0
self.drift_denom = 0
self.drift_cnt = 0
self.set_period_ns(period_ns)
self.ts_tod_s = 0 self.ts_tod_s = 0
self.ts_tod_ns = 0 self.ts_tod_ns = 0
self.ts_tod_fns = 0 self.ts_tod_fns = 0
@@ -94,26 +96,29 @@ class PtpClock(Reset):
def set_period(self, ns, fns): def set_period(self, ns, fns):
self.period_ns = int(ns) self.period_ns = int(ns)
self.period_fns = int(fns) & 0xffff self.period_fns = int(fns) & 0xffffffff
def set_drift(self, num, denom): def set_drift(self, num, denom):
self.drift_num = int(num) self.drift_num = int(num)
self.drift_denom = int(denom) self.drift_denom = int(denom)
def set_period_ns(self, t): def set_period_ns(self, t):
drift, period = math.modf(t*2**16) t = Decimal(t)
period, drift = self.ctx.divmod(Decimal(t) * Decimal(2**32), Decimal(1))
period = int(period) period = int(period)
frac = Fraction(drift).limit_denominator(2**16) frac = Fraction(drift).limit_denominator(2**16-1)
self.period_ns = period >> 16 self.set_period(period >> 32, period & 0xffffffff)
self.period_fns = period & 0xffff self.set_drift(frac.numerator, frac.denominator)
self.drift_num = frac.numerator
self.drift_denom = frac.denominator self.log.info("Set period: %s ns", t)
self.log.info("Period: 0x%x ns 0x%08x fns", self.period_ns, self.period_fns)
self.log.info("Drift: 0x%04x / 0x%04x fns", self.drift_num, self.drift_denom)
def get_period_ns(self): def get_period_ns(self):
p = ((self.period_ns << 16) | self.period_fns) / 2**16 p = Decimal((self.period_ns << 32) | self.period_fns)
if self.drift_denom: if self.drift_denom:
return p + self.drift_num / self.drift_rate / 2**16 p += Decimal(self.drift_num) / Decimal(self.drift_denom)
return p return p / Decimal(2**32)
def set_ts_tod(self, ts_s, ts_ns, ts_fns): def set_ts_tod(self, ts_s, ts_ns, ts_fns):
self.ts_tod_s = int(ts_s) self.ts_tod_s = int(ts_s)
@@ -123,31 +128,37 @@ class PtpClock(Reset):
def set_ts_tod_96(self, ts): def set_ts_tod_96(self, ts):
ts = int(ts) ts = int(ts)
self.set_ts_tod(ts >> 48, (ts >> 32) & 0x3fffffff, ts & 0xffff) self.set_ts_tod(ts >> 48, (ts >> 32) & 0x3fffffff, (ts & 0xffff) << 16)
def set_ts_tod_ns(self, t): def set_ts_tod_ns(self, t):
self.set_ts_tod_s(t*1e-9) ts_s, ts_ns = self.ctx.divmod(Decimal(t), Decimal(1000000000))
ts_s = ts_s.scaleb(-9).to_integral_value()
ts_ns, ts_fns = self.ctx.divmod(ts_ns, Decimal(1))
ts_ns = ts_ns.to_integral_value()
ts_fns = (ts_fns * Decimal(2**32)).to_integral_value()
self.set_ts_tod(ts_s, ts_ns, ts_fns)
def set_ts_tod_s(self, t): def set_ts_tod_s(self, t):
ts_ns, ts_s = math.modf(t) self.set_ts_tod_ns(Decimal(t).scaleb(9, self.ctx))
ts_ns *= 1e9
ts_fns, ts_ns = math.modf(ts_ns) def set_ts_tod_sim_time(self):
ts_fns *= 2**16 self.set_ts_tod_ns(Decimal(get_sim_time('fs')).scaleb(-6))
self.set_ts_tod(ts_s, ts_ns, ts_fns)
def get_ts_tod(self): def get_ts_tod(self):
return (self.ts_tod_s, self.ts_tod_ns, self.ts_tod_fns) return (self.ts_tod_s, self.ts_tod_ns, self.ts_tod_fns)
def get_ts_tod_96(self): def get_ts_tod_96(self):
ts_s, ts_ns, ts_fns = self.get_ts_tod() ts_s, ts_ns, ts_fns = self.get_ts_tod()
return (ts_s << 48) | (ts_ns << 16) | ts_fns return (ts_s << 48) | (ts_ns << 16) | (ts_fns >> 16)
def get_ts_tod_ns(self): def get_ts_tod_ns(self):
ts_s, ts_ns, ts_fns = self.get_ts_tod() ts_s, ts_ns, ts_fns = self.get_ts_tod()
return ts_s*1e9+ts_ns+ts_fns/2**16 ns = Decimal(ts_fns) / Decimal(2**32)
ns = self.ctx.add(ns, Decimal(ts_ns))
return self.ctx.add(ns, Decimal(ts_s).scaleb(9))
def get_ts_tod_s(self): def get_ts_tod_s(self):
return self.get_ts_tod_ns()*1e-9 return self.get_ts_tod_ns().scaleb(-9, self.ctx)
def set_ts_rel(self, ts_ns, ts_fns): def set_ts_rel(self, ts_ns, ts_fns):
self.ts_rel_ns = int(ts_ns) self.ts_rel_ns = int(ts_ns)
@@ -159,12 +170,16 @@ class PtpClock(Reset):
self.set_ts_rel(ts >> 16, (ts & 0xffff) << 16) self.set_ts_rel(ts >> 16, (ts & 0xffff) << 16)
def set_ts_rel_ns(self, t): def set_ts_rel_ns(self, t):
ts_fns, ts_ns = math.modf(t) ts_ns, ts_fns = self.ctx.divmod(Decimal(t), Decimal(1))
ts_fns *= 2**16 ts_ns = ts_ns.to_integral_value()
ts_fns = (ts_fns * Decimal(2**32)).to_integral_value()
self.set_ts_rel(ts_ns, ts_fns) self.set_ts_rel(ts_ns, ts_fns)
def set_ts_rel_s(self, t): def set_ts_rel_s(self, t):
self.set_ts_rel_ns(t*1e9) self.set_ts_rel_ns(Decimal(t).scaleb(9, self.ctx))
def set_ts_rel_sim_time(self):
self.set_ts_rel_ns(Decimal(get_sim_time('fs')).scaleb(-6))
def get_ts_rel(self): def get_ts_rel(self):
return (self.ts_rel_ns, self.ts_rel_fns) return (self.ts_rel_ns, self.ts_rel_fns)
@@ -175,10 +190,10 @@ class PtpClock(Reset):
def get_ts_rel_ns(self): def get_ts_rel_ns(self):
ts_ns, ts_fns = self.get_ts_rel() ts_ns, ts_fns = self.get_ts_rel()
return ts_ns + ts_fns/2**16 return self.ctx.add(Decimal(ts_fns) / Decimal(2**32), Decimal(ts_ns))
def get_ts_rel_s(self): def get_ts_rel_s(self):
return self.get_ts_rel()*1e-9 return self.get_ts_rel_ns().scaleb(-9, self.ctx)
def _handle_reset(self, state): def _handle_reset(self, state):
if state: if state:
@@ -219,36 +234,39 @@ class PtpClock(Reset):
if self.pps is not None: if self.pps is not None:
self.pps.value = 0 self.pps.value = 0
# increment 96 bit timestamp # increment tod bit timestamp
if self.ts_tod is not None or self.pps is not None: self.ts_tod_fns += (self.period_ns << 32) + self.period_fns
t = ((self.ts_tod_ns << 16) + self.ts_tod_fns) + ((self.period_ns << 16) + self.period_fns)
if self.drift_denom and self.drift_cnt == 0: if self.drift_denom and self.drift_cnt == 0:
t += self.drift_num self.ts_tod_fns += self.drift_num
if t > (1000000000 << 16): ns_inc = self.ts_tod_fns >> 32
self.ts_tod_fns &= 0xffffffff
self.ts_tod_ns += ns_inc
if self.ts_tod_ns >= 1000000000:
self.ts_tod_s += 1 self.ts_tod_s += 1
t -= (1000000000 << 16) self.ts_tod_ns -= 1000000000
if self.pps is not None: if self.pps is not None:
self.pps.value = 1 self.pps.value = 1
self.ts_tod_fns = t & 0xffff
self.ts_tod_ns = t >> 16
if self.ts_tod is not None: if self.ts_tod is not None:
self.ts_tod.value = (self.ts_tod_s << 48) | (self.ts_tod_ns << 16) | (self.ts_tod_fns) self.ts_tod.value = (self.ts_tod_s << 48) | (self.ts_tod_ns << 16) | (self.ts_tod_fns >> 16)
# increment 64 bit timestamp # increment rel bit timestamp
if self.ts_rel is not None: self.ts_rel_fns += (self.period_ns << 32) + self.period_fns
t = ((self.ts_rel_ns << 16) + self.ts_rel_fns) + ((self.period_ns << 16) + self.period_fns)
if self.drift_denom and self.drift_cnt == 0: if self.drift_denom and self.drift_cnt == 0:
t += self.drift_num self.ts_rel_fns += self.drift_num
self.ts_rel_fns = t & 0xffff ns_inc = self.ts_rel_fns >> 32
self.ts_rel_ns = t >> 16 self.ts_rel_fns &= 0xffffffff
self.ts_rel.value = (self.ts_rel_ns << 16) | self.ts_rel_fns self.ts_rel_ns = (self.ts_rel_ns + ns_inc) & 0xffffffffffff
if self.ts_rel is not None:
self.ts_rel.value = (self.ts_rel_ns << 16) | (self.ts_rel_fns >> 16)
if self.drift_denom: if self.drift_denom:
if self.drift_cnt > 0: if self.drift_cnt > 0:
@@ -273,6 +291,8 @@ class PtpClockSimTime:
super().__init__(*args, **kwargs) super().__init__(*args, **kwargs)
self.ctx = Context(prec=60)
self.ts_tod_s = 0 self.ts_tod_s = 0
self.ts_tod_ns = 0 self.ts_tod_ns = 0
self.ts_tod_fns = 0 self.ts_tod_fns = 0
@@ -296,11 +316,16 @@ class PtpClockSimTime:
def get_ts_tod_96(self): def get_ts_tod_96(self):
ts_s, ts_ns, ts_fns = self.get_ts_tod() ts_s, ts_ns, ts_fns = self.get_ts_tod()
return (ts_s << 48) | (ts_ns << 16) | ts_fns return (ts_s << 48) | (ts_ns << 16) | (ts_fns >> 16)
def get_ts_tod_ns(self): def get_ts_tod_ns(self):
ts_s, ts_ns, ts_fns = self.get_ts_tod() ts_s, ts_ns, ts_fns = self.get_ts_tod()
return ts_s*1e9+ts_ns+ts_fns/2**16 ns = Decimal(ts_fns) / Decimal(2**32)
ns = self.ctx.add(ns, Decimal(ts_ns))
return self.ctx.add(ns, Decimal(ts_s).scaleb(9))
def get_ts_tod_s(self):
return self.get_ts_tod_ns().scaleb(-9, self.ctx)
def get_ts_rel(self): def get_ts_rel(self):
return (self.ts_rel_ns, self.ts_rel_fns) return (self.ts_rel_ns, self.ts_rel_fns)
@@ -311,10 +336,10 @@ class PtpClockSimTime:
def get_ts_rel_ns(self): def get_ts_rel_ns(self):
ts_ns, ts_fns = self.get_ts_rel() ts_ns, ts_fns = self.get_ts_rel()
return ts_ns + ts_fns/2**16 return self.ctx.add(Decimal(ts_fns) / Decimal(2**32), Decimal(ts_ns))
def get_ts_rel_s(self): def get_ts_rel_s(self):
return self.get_ts_rel()*1e-9 return self.get_ts_rel_ns().scaleb(-9, self.ctx)
async def _run(self): async def _run(self):
clock_edge_event = RisingEdge(self.clock) clock_edge_event = RisingEdge(self.clock)
@@ -322,12 +347,15 @@ class PtpClockSimTime:
while True: while True:
await clock_edge_event await clock_edge_event
self.ts_rel_fns, self.ts_rel_ns = math.modf(get_sim_time('ns')) ts_ns, ts_fns = self.ctx.divmod(Decimal(get_sim_time('fs')).scaleb(-6), Decimal(1))
self.ts_rel_ns = int(self.ts_rel_ns) self.ts_rel_ns = int(ts_ns.to_integral_value()) & 0xffffffffffff
self.ts_rel_fns = int(self.ts_rel_fns*0x10000) self.ts_rel_fns = int((ts_fns * Decimal(2**16)).to_integral_value())
self.ts_tod_s, self.ts_tod_ns = divmod(self.ts_rel_ns, 1000000000) ts_s, ts_ns = self.ctx.divmod(ts_ns, Decimal(1000000000))
self.ts_tod_s = int(ts_s.scaleb(-9).to_integral_value())
self.ts_tod_ns = int(ts_ns.to_integral_value())
self.ts_tod_fns = self.ts_rel_fns self.ts_tod_fns = self.ts_rel_fns
if self.ts_tod is not None: if self.ts_tod is not None:

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@@ -25,6 +25,7 @@ THE SOFTWARE.
import logging import logging
import os import os
from decimal import Decimal
import cocotb_test.simulator import cocotb_test.simulator
@@ -66,6 +67,14 @@ class TB:
await RisingEdge(self.dut.clk) await RisingEdge(self.dut.clk)
await RisingEdge(self.dut.clk) await RisingEdge(self.dut.clk)
def get_ts_tod_ns(self):
ts = self.dut.ts_tod.value.integer
return Decimal(ts >> 48).scaleb(9) + (Decimal(ts & 0xffffffffffff) / Decimal(2**16))
def get_ts_rel_ns(self):
ts = self.dut.ts_rel.value.integer
return Decimal(ts) / Decimal(2**16)
@cocotb.test() @cocotb.test()
async def run_default_rate(dut): async def run_default_rate(dut):
@@ -75,32 +84,32 @@ async def run_default_rate(dut):
await tb.reset() await tb.reset()
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
start_time = get_sim_time('sec') start_time = Decimal(get_sim_time('fs')).scaleb(-6)
start_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) start_ts_tod = tb.get_ts_tod_ns()
start_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 start_ts_rel = tb.get_ts_rel_ns()
await ClockCycles(dut.clk, 10000) await ClockCycles(dut.clk, 10000)
stop_time = get_sim_time('sec') stop_time = Decimal(get_sim_time('fs')).scaleb(-6)
stop_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) stop_ts_tod = tb.get_ts_tod_ns()
stop_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 stop_ts_rel = tb.get_ts_rel_ns()
time_delta = stop_time-start_time time_delta = stop_time-start_time
ts_tod_delta = stop_ts_tod-start_ts_tod ts_tod_delta = stop_ts_tod-start_ts_tod
ts_rel_delta = stop_ts_rel-start_ts_rel ts_rel_delta = stop_ts_rel-start_ts_rel
tb.log.info("sim time delta : %g s", time_delta) tb.log.info("sim time delta : %s ns", time_delta)
tb.log.info("ToD ts delta : %g s", ts_tod_delta) tb.log.info("ToD ts delta : %s ns", ts_tod_delta)
tb.log.info("rel ts delta : %g s", ts_rel_delta) tb.log.info("rel ts delta : %s ns", ts_rel_delta)
ts_tod_diff = time_delta - ts_tod_delta ts_tod_diff = time_delta - ts_tod_delta
ts_rel_diff = time_delta - ts_rel_delta ts_rel_diff = time_delta - ts_rel_delta
tb.log.info("ToD ts diff : %g s", ts_tod_diff) tb.log.info("ToD ts diff : %s ns", ts_tod_diff)
tb.log.info("rel ts diff : %g s", ts_rel_diff) tb.log.info("rel ts diff : %s ns", ts_rel_diff)
assert abs(ts_tod_diff) < 1e-12 assert abs(ts_tod_diff) < 1e-3
assert abs(ts_rel_diff) < 1e-12 assert abs(ts_rel_diff) < 1e-3
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
@@ -118,36 +127,36 @@ async def run_load_timestamps(dut):
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
assert dut.ts_tod.value.integer == 12345678*2**16 + (tb.ptp_clock.period_ns << 16) + tb.ptp_clock.period_fns assert dut.ts_tod.value.integer == (12345678 << 16) + (tb.ptp_clock.period_ns << 16) + (tb.ptp_clock.period_fns >> 16)
assert dut.ts_rel.value.integer == 12345678*2**16 + (tb.ptp_clock.period_ns << 16) + tb.ptp_clock.period_fns assert dut.ts_rel.value.integer == (12345678 << 16) + (tb.ptp_clock.period_ns << 16) + (tb.ptp_clock.period_fns >> 16)
assert dut.ts_step.value.integer == 1 assert dut.ts_step.value.integer == 1
start_time = get_sim_time('sec') start_time = Decimal(get_sim_time('fs')).scaleb(-6)
start_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) start_ts_tod = tb.get_ts_tod_ns()
start_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 start_ts_rel = tb.get_ts_rel_ns()
await ClockCycles(dut.clk, 2000) await ClockCycles(dut.clk, 2000)
stop_time = get_sim_time('sec') stop_time = Decimal(get_sim_time('fs')).scaleb(-6)
stop_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) stop_ts_tod = tb.get_ts_tod_ns()
stop_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 stop_ts_rel = tb.get_ts_rel_ns()
time_delta = stop_time-start_time time_delta = stop_time-start_time
ts_tod_delta = stop_ts_tod-start_ts_tod ts_tod_delta = stop_ts_tod-start_ts_tod
ts_rel_delta = stop_ts_rel-start_ts_rel ts_rel_delta = stop_ts_rel-start_ts_rel
tb.log.info("sim time delta : %g s", time_delta) tb.log.info("sim time delta : %s ns", time_delta)
tb.log.info("ToD ts delta : %g s", ts_tod_delta) tb.log.info("ToD ts delta : %s ns", ts_tod_delta)
tb.log.info("rel ts delta : %g s", ts_rel_delta) tb.log.info("rel ts delta : %s ns", ts_rel_delta)
ts_tod_diff = time_delta - ts_tod_delta ts_tod_diff = time_delta - ts_tod_delta
ts_rel_diff = time_delta - ts_rel_delta ts_rel_diff = time_delta - ts_rel_delta
tb.log.info("ToD ts diff : %g s", ts_tod_diff) tb.log.info("ToD ts diff : %s ns", ts_tod_diff)
tb.log.info("rel ts diff : %g s", ts_rel_diff) tb.log.info("rel ts diff : %s ns", ts_rel_diff)
assert abs(ts_tod_diff) < 1e-12 assert abs(ts_tod_diff) < 1e-3
assert abs(ts_rel_diff) < 1e-12 assert abs(ts_rel_diff) < 1e-3
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
@@ -166,9 +175,9 @@ async def run_seconds_increment(dut):
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
start_time = get_sim_time('sec') start_time = Decimal(get_sim_time('fs')).scaleb(-6)
start_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) start_ts_tod = tb.get_ts_tod_ns()
start_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 start_ts_rel = tb.get_ts_rel_ns()
saw_pps = False saw_pps = False
@@ -182,26 +191,26 @@ async def run_seconds_increment(dut):
assert saw_pps assert saw_pps
stop_time = get_sim_time('sec') stop_time = Decimal(get_sim_time('fs')).scaleb(-6)
stop_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) stop_ts_tod = tb.get_ts_tod_ns()
stop_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 stop_ts_rel = tb.get_ts_rel_ns()
time_delta = stop_time-start_time time_delta = stop_time-start_time
ts_tod_delta = stop_ts_tod-start_ts_tod ts_tod_delta = stop_ts_tod-start_ts_tod
ts_rel_delta = stop_ts_rel-start_ts_rel ts_rel_delta = stop_ts_rel-start_ts_rel
tb.log.info("sim time delta : %g s", time_delta) tb.log.info("sim time delta : %s ns", time_delta)
tb.log.info("ToD ts delta : %g s", ts_tod_delta) tb.log.info("ToD ts delta : %s ns", ts_tod_delta)
tb.log.info("rel ts delta : %g s", ts_rel_delta) tb.log.info("rel ts delta : %s ns", ts_rel_delta)
ts_tod_diff = time_delta - ts_tod_delta ts_tod_diff = time_delta - ts_tod_delta
ts_rel_diff = time_delta - ts_rel_delta ts_rel_diff = time_delta - ts_rel_delta
tb.log.info("ToD ts diff : %g s", ts_tod_diff) tb.log.info("ToD ts diff : %s ns", ts_tod_diff)
tb.log.info("rel ts diff : %g s", ts_rel_diff) tb.log.info("rel ts diff : %s ns", ts_rel_diff)
assert abs(ts_tod_diff) < 1e-12 assert abs(ts_tod_diff) < 1e-3
assert abs(ts_rel_diff) < 1e-12 assert abs(ts_rel_diff) < 1e-3
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
@@ -214,36 +223,35 @@ async def run_frequency_adjustment(dut):
await tb.reset() await tb.reset()
tb.ptp_clock.period_ns = 0x6 tb.ptp_clock.set_period(0x6, 0x66240000)
tb.ptp_clock.period_fns = 0x6624
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
start_time = get_sim_time('sec') start_time = Decimal(get_sim_time('fs')).scaleb(-6)
start_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) start_ts_tod = tb.get_ts_tod_ns()
start_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 start_ts_rel = tb.get_ts_rel_ns()
await ClockCycles(dut.clk, 10000) await ClockCycles(dut.clk, 10000)
stop_time = get_sim_time('sec') stop_time = Decimal(get_sim_time('fs')).scaleb(-6)
stop_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) stop_ts_tod = tb.get_ts_tod_ns()
stop_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 stop_ts_rel = tb.get_ts_rel_ns()
time_delta = stop_time-start_time time_delta = stop_time-start_time
ts_tod_delta = stop_ts_tod-start_ts_tod ts_tod_delta = stop_ts_tod-start_ts_tod
ts_rel_delta = stop_ts_rel-start_ts_rel ts_rel_delta = stop_ts_rel-start_ts_rel
tb.log.info("sim time delta : %g s", time_delta) tb.log.info("sim time delta : %s ns", time_delta)
tb.log.info("ToD ts delta : %g s", ts_tod_delta) tb.log.info("ToD ts delta : %s ns", ts_tod_delta)
tb.log.info("rel ts delta : %g s", ts_rel_delta) tb.log.info("rel ts delta : %s ns", ts_rel_delta)
ts_tod_diff = time_delta - ts_tod_delta * 6.4/(6+(0x6624+2/5)/2**16) ts_tod_diff = time_delta - ts_tod_delta * Decimal(6.4)/tb.ptp_clock.get_period_ns()
ts_rel_diff = time_delta - ts_rel_delta * 6.4/(6+(0x6624+2/5)/2**16) ts_rel_diff = time_delta - ts_rel_delta * Decimal(6.4)/tb.ptp_clock.get_period_ns()
tb.log.info("ToD ts diff : %g s", ts_tod_diff) tb.log.info("ToD ts diff : %s ns", ts_tod_diff)
tb.log.info("rel ts diff : %g s", ts_rel_diff) tb.log.info("rel ts diff : %s ns", ts_rel_diff)
assert abs(ts_tod_diff) < 1e-12 assert abs(ts_tod_diff) < 1e-3
assert abs(ts_rel_diff) < 1e-12 assert abs(ts_rel_diff) < 1e-3
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
@@ -256,36 +264,35 @@ async def run_drift_adjustment(dut):
await tb.reset() await tb.reset()
tb.ptp_clock.drift_num = 20 tb.ptp_clock.set_drift(20000, 5)
tb.ptp_clock.drift_denom = 5
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
start_time = get_sim_time('sec') start_time = Decimal(get_sim_time('fs')).scaleb(-6)
start_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) start_ts_tod = tb.get_ts_tod_ns()
start_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 start_ts_rel = tb.get_ts_rel_ns()
await ClockCycles(dut.clk, 10000) await ClockCycles(dut.clk, 10000)
stop_time = get_sim_time('sec') stop_time = Decimal(get_sim_time('fs')).scaleb(-6)
stop_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) stop_ts_tod = tb.get_ts_tod_ns()
stop_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 stop_ts_rel = tb.get_ts_rel_ns()
time_delta = stop_time-start_time time_delta = stop_time-start_time
ts_tod_delta = stop_ts_tod-start_ts_tod ts_tod_delta = stop_ts_tod-start_ts_tod
ts_rel_delta = stop_ts_rel-start_ts_rel ts_rel_delta = stop_ts_rel-start_ts_rel
tb.log.info("sim time delta : %g s", time_delta) tb.log.info("sim time delta : %s ns", time_delta)
tb.log.info("ToD ts delta : %g s", ts_tod_delta) tb.log.info("ToD ts delta : %s ns", ts_tod_delta)
tb.log.info("rel ts delta : %g s", ts_rel_delta) tb.log.info("rel ts delta : %s ns", ts_rel_delta)
ts_tod_diff = time_delta - ts_tod_delta * 6.4/(6+(0x6666+20/5)/2**16) ts_tod_diff = time_delta - ts_tod_delta * Decimal(6.4)/tb.ptp_clock.get_period_ns()
ts_rel_diff = time_delta - ts_rel_delta * 6.4/(6+(0x6666+20/5)/2**16) ts_rel_diff = time_delta - ts_rel_delta * Decimal(6.4)/tb.ptp_clock.get_period_ns()
tb.log.info("ToD ts diff : %g s", ts_tod_diff) tb.log.info("ToD ts diff : %s ns", ts_tod_diff)
tb.log.info("rel ts diff : %g s", ts_rel_diff) tb.log.info("rel ts diff : %s ns", ts_rel_diff)
assert abs(ts_tod_diff) < 1e-12 assert abs(ts_tod_diff) < 1e-3
assert abs(ts_rel_diff) < 1e-12 assert abs(ts_rel_diff) < 1e-3
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
await RisingEdge(dut.clk) await RisingEdge(dut.clk)

View File

@@ -25,6 +25,7 @@ THE SOFTWARE.
import logging import logging
import os import os
from decimal import Decimal
import cocotb_test.simulator import cocotb_test.simulator
@@ -52,6 +53,14 @@ class TB:
clock=dut.clk clock=dut.clk
) )
def get_ts_tod_ns(self):
ts = self.dut.ts_tod.value.integer
return Decimal(ts >> 48).scaleb(9) + (Decimal(ts & 0xffffffffffff) / Decimal(2**16))
def get_ts_rel_ns(self):
ts = self.dut.ts_rel.value.integer
return Decimal(ts) / Decimal(2**16)
@cocotb.test() @cocotb.test()
async def run_test(dut): async def run_test(dut):
@@ -62,32 +71,32 @@ async def run_test(dut):
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
start_time = get_sim_time('sec') start_time = Decimal(get_sim_time('fs')).scaleb(-6)
start_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) start_ts_tod = tb.get_ts_tod_ns()
start_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 start_ts_rel = tb.get_ts_rel_ns()
await ClockCycles(dut.clk, 10000) await ClockCycles(dut.clk, 10000)
stop_time = get_sim_time('sec') stop_time = Decimal(get_sim_time('fs')).scaleb(-6)
stop_ts_tod = (dut.ts_tod.value.integer >> 48) + ((dut.ts_tod.value.integer & 0xffffffffffff)/2**16*1e-9) stop_ts_tod = tb.get_ts_tod_ns()
stop_ts_rel = dut.ts_rel.value.integer/2**16*1e-9 stop_ts_rel = tb.get_ts_rel_ns()
time_delta = stop_time-start_time time_delta = stop_time-start_time
ts_tod_delta = stop_ts_tod-start_ts_tod ts_tod_delta = stop_ts_tod-start_ts_tod
ts_rel_delta = stop_ts_rel-start_ts_rel ts_rel_delta = stop_ts_rel-start_ts_rel
tb.log.info("sim time delta : %g s", time_delta) tb.log.info("sim time delta : %s ns", time_delta)
tb.log.info("ToD ts delta : %g s", ts_tod_delta) tb.log.info("ToD ts delta : %s ns", ts_tod_delta)
tb.log.info("rel ts delta : %g s", ts_rel_delta) tb.log.info("rel ts delta : %s ns", ts_rel_delta)
ts_tod_diff = time_delta - ts_tod_delta ts_tod_diff = time_delta - ts_tod_delta
ts_rel_diff = time_delta - ts_rel_delta ts_rel_diff = time_delta - ts_rel_delta
tb.log.info("ToD ts diff : %g s", ts_tod_diff) tb.log.info("ToD ts diff : %s ns", ts_tod_diff)
tb.log.info("rel ts diff : %g s", ts_rel_diff) tb.log.info("rel ts diff : %s ns", ts_rel_diff)
assert abs(ts_tod_diff) < 1e-12 assert abs(ts_tod_diff) < 1e-3
assert abs(ts_rel_diff) < 1e-12 assert abs(ts_rel_diff) < 1e-3
await RisingEdge(dut.clk) await RisingEdge(dut.clk)
await RisingEdge(dut.clk) await RisingEdge(dut.clk)