4410: modify ram example

* Use `prepare()` to init the arrays, would be great if the value can be prepared there. However, the type check was not happy about it.
* Separate RAM configuration into a separate function
* Separate DDS init, digital attenuation & switch config in an init function
* Use `dds.set()`. It is supposed to look simple.

All these are to avoid repeating the long code in the coming RAM+SYNC example.
This commit is contained in:
occheung 2021-12-07 16:21:53 +08:00
parent 0dbf7a70c4
commit 011d63f3eb
1 changed files with 33 additions and 23 deletions

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@ -457,39 +457,49 @@ It can be negated by adjusting the \texttt{phase} parameter.
\newpage
\subsection{DDS RAM Modulation (AD9910 Only)}
This examples demonstrates that the RF signal can be modulated by amplitude using the RAM modulation feature of AD9910.
Set field \texttt{dds} as an Urukul channel, \texttt{cpld} as the corresponding Urukul CPLD.
By default, RAM profiles are programmed to profile 0.
\begin{minted}{python}
from artiq.coredevice.ad9910 import RAM_MODE_CONT_RAMPUP
def prepare(self):
self.amp = [0.0, 0.0, 0.0, 0.7, 0.0, 0.7, 0.7] # Reversed Order
self.asf_ram = [0] * len(self.amp)
@kernel
def init_dds(self, dds):
self.core.break_realtime()
dds.init()
dds.set_att(6.)
dds.cfg_sw(True)
@kernel
def configure_ram_mode(self, dds):
self.core.break_realtime()
dds.set_cfr1(ram_enable=0)
self.cpld.io_update.pulse_mu(8)
self.cpld.set_profile(0) # Enable the corresponding RAM profile
# Profile 0 is the default
dds.set_profile_ram(start=0, end=len(self.asf_ram)-1,
step=250, profile=0, mode=RAM_MODE_CONT_RAMPUP)
self.cpld.io_update.pulse_mu(8)
dds.amplitude_to_ram(self.amp, self.asf_ram)
dds.write_ram(self.asf_ram)
dds.set(10*MHz, profile=-1)
# Pass osk_enable=1 to set_cfr1() if it is not an amplitude RAM
dds.set_cfr1(ram_enable=1, ram_destination=RAM_DEST_ASF)
self.cpld.io_update.pulse_mu(8)
@kernel
def run(self):
self.core.reset()
self.core.break_realtime()
self.cpld.init()
self.dds.init()
self.core.break_realtime()
self.profile0_set()
self.dds.set_att(6.)
self.dds.sw.on()
self.cpld.set_profile(0)
@kernel
def profile0_set(self):
self.dds.set_cfr1(ram_enable = 0)
self.cpld.set_profile(0)
amp_ram = [0.0, 0.0, 0.0, 0.7, 0.0, 0.7, 0.7] # Reversed Order
asf_ram = [0] * len(amp_ram)
self.dds.set_profile_ram(start=0, end=len(amp_ram)-1,
step=250, profile=0, mode=RAM_MODE_CONT_RAMPUP)
self.cpld.io_update.pulse_mu(8)
self.dds.amplitude_to_ram(amp_ram, asf_ram)
self.dds.write_ram(asf_ram)
self.dds.set_cfr1(ram_enable=1, ram_destination=RAM_DEST_ASF)
self.dds.set_frequency(10*MHz)
self.cpld.io_update.pulse_mu(8)
self.init_dds(self.dds0)
self.configure_ram_mode(self.dds0)
\end{minted}
The generated RF output of the above example consists of the following features in sequence: