forked from M-Labs/artiq
phaser: rename get_next_frame_timestamp() to get_next_frame_mu()
and implement review comments (PR #1749) Signed-off-by: Etienne Wodey <etienne.wodey@aqt.eu>
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@ -94,7 +94,7 @@ class Phaser:
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:class:`PhaserOscillator` or :class:`PhaserChannel` DUC parameters all the
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way to the DAC outputs is deterministic. This enables deterministic
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absolute phase with respect to other RTIO input and output events
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(see `get_next_frame_timestamp()`).
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(see `get_next_frame_mu()`).
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The four analog DAC outputs are passed through anti-aliasing filters.
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@ -476,28 +476,23 @@ class Phaser:
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@kernel
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def measure_frame_timestamp(self):
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"""Perform a register read and record the exact frame timing in `self.frame_tstamp`.
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"""Measure the timestamp of an arbitrary frame and store it in `self.frame_tstamp`.
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Deterministic timing requires updates to be schedule at multiples of `self.t_frame` later.
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See `get_next_frame_timestamp()`.
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To be used as reference for aligning updates to the FastLink frames.
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See `get_next_frame_mu()`.
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"""
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rtio_output((self.channel_base << 8) | (PHASER_ADDR_BOARD_ID & 0x7f), 0) # can read any register
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delay_mu(int64(self.t_frame))
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self.frame_tstamp = rtio_input_timestamp(rtio_get_counter() + 0xffffff, self.channel_base)
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delay(10*ms)
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rtio_output(self.channel_base << 8, 0) # read any register
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self.frame_tstamp = rtio_input_timestamp(rtio_get_counter() + 125_000, self.channel_base)
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delay(100 * us)
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@kernel
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def get_next_frame_timestamp(self, after_timestamp_mu = int64(-1)):
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"""Return the RTIO timestamp of the next frame after `after_timestamp_mu`.
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def get_next_frame_mu(self):
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"""Return the timestamp of the frame strictly after `now_mu()`.
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If `after_timestamp_mu < 0`, return the next frame after `now_mu()`.
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Updates scheduled at this timestamp and multiples of `self.t_frame` later will
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have deterministic latency with respect to the RTIO timeline.
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Register updates (DUC, DAC, TRF, etc.) scheduled at this timestamp and multiples
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of `self.t_frame` later will have deterministic latency to output.
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"""
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if after_timestamp_mu < 0:
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after_timestamp_mu = now_mu()
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n = int64((after_timestamp_mu - self.frame_tstamp) / self.t_frame)
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n = int64((now_mu() - self.frame_tstamp) / self.t_frame)
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return self.frame_tstamp + (n + 1) * self.t_frame
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@kernel
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