2118-2128: add t_min info from #26

This commit is contained in:
occheung 2022-07-26 18:26:52 +08:00
parent 7d993a4800
commit 440b3ef3df
2 changed files with 50 additions and 0 deletions

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@ -606,6 +606,15 @@ Typically, with the coarse RTIO clock at 125 MHz, a \texttt{ClockGen} channel ca
\inputcolorboxminted{firstline=72,lastline=75}{examples/ttl.py}
\newpage
\subsection{Maximum Sustained Event Separation}
The maximum sustained event separation is the least amount of time separation between input gated events, in which all gated edges can be continuously \& reliabily timestamped by the RTIO system without causing \texttt{RTIOOverflow} exceptions.
The following \texttt{run()} function finds the separation by approximating the time of running \texttt{timestamp\char`_mu()} as a constant. Import the \texttt{time} library to use \texttt{time.sleep()}.
\inputcolorboxminted{firstline=60,lastline=92}{examples/ttl_in.py}
The result fluctuates at around 650ns with Kasli v1.1.
\section{Ordering Information}
To order, please visit \url{https://m-labs.hk} and select the 2118 BNC-TTL/2128 SMA-TTL in the ARTIQ Sinara crate configuration tool. The card may also be ordered separately by writing to \url{mailto:sales@m-labs.hk}.

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@ -49,3 +49,44 @@ class ExternalTrigger(EnvExperiment):
timestamp_mu = self.ttlin.timestamp_mu(gate_end_mu)
at_mu(timestamp_mu + self.core.seconds_to_mu(10*ms))
self.ttlout.pulse(1*us)
class MeanTimestampDuration(EnvExperiment):
def build(self):
self.setattr_device("core")
self.ttlin = self.get_device("ttl0")
self.ttlclk = self.get_device("ttl7")
@kernel
def get_timestamp_duration(self, pulse_num) -> TInt64:
self.core.break_realtime()
delay(1*ms)
gate_start_mu = now_mu()
# Start input gate & advance timeline cursor to gate_end_mu
gate_end_mu = self.ttlin.gate_rising(1*ms)
at_mu(gate_start_mu)
self.ttlclk.set_mu(0x800000)
delay(16*pulse_num*ns)
self.ttlclk.set_mu(0)
# Guarantee t0 > gate_end_mu
# Otherwise timestamp_mu may wait for pulses till gate_end_mu
self.rpc_sleep(1*ms)
t0 = self.core.get_rtio_counter_mu()
while self.ttlin.timestamp_mu(gate_end_mu) >= 0:
pass
t1 = self.core.get_rtio_counter_mu()
return t1 - t0
@rpc
def rpc_sleep(self, duration):
time.sleep(duration)
@kernel
def run(self):
self.core.reset()
t64 = self.get_timestamp_duration(64)
t8 = self.get_timestamp_duration(8)
print("Mean timestamp_mu duration:")
print(self.core.mu_to_seconds((t64 - t8)/((64 + 1) - (8 + 1))))