These scripts require CPSW and its 'pycpsw' wrapper for python.
This 'driver' script can be used to initialize the BPM firmware and in particular, the simulator.
Prior to executing this script the 'defaults.yaml' that is distributed with the firmware image should be loaded to do basic initialization.
The classes and routines defined in this file are designed to program the filter coefficients of the BPM simulator.
Starting with a standard description of a linear system
(e.g., as a transfer function) the LinSys class
transforms the system into a parallel representation
of complex single-order (class firstOrderSys) sub-systems.
The single-order systems are expanded with additional, cancelling pole/zero pairs to obtain a representation that permits a pipelined implementation.
Further transformations are applied to extract coefficients that are suitable for the particular firmware implementation (this includes conversion into the proper 18-bit fixed-point representation etc.).
Two wrappers mkCavitySystem and mkStriplineSystem are
available which compute appropriate linear systems and
simulator coefficients from high-level parameters such as
cavity center-frequencies and Qs.
mkStriplineSystem synthesizes 4'th order Chebyshev
band-pass filters from a given center-frequency and bandwidth,
one for each stripline channel. The individual center-frequencies
are slightly randomized ("tolerance") around the specified value.
The frequences should be normalized to the sampling frequency.
mkStriplineSystem( fo_f = 300/370, bw_f = 40/370 )
mkCavitySystem behaves exactly like its stripline counterpart
but in addition to the band-pass filter it features a second-
order resonator for simulating the cavity response. The center
frequency and Q of the cavity can be specified individually for
each channel.
Fcav = [0, 38.2/fs , 30.3/fs , 37.2/fs ]
Qcav = [0, 38.2/2.1, 30.3/1.25, 37.2/3.3]
Fflt = 35/370
Bflt = 30/370
mkCavitySystem( [ 0, 28.5/370, 28.8/370, 29/370 ], [ 0, 73, 68, 50 ]
This script defines the SIM class which interfaces to the
registers of the simulator. E.g., it has methods to start/stop
the simulator or download coefficients without the user having
to remember the register names etc.
Utility class to load a firmware-description YAML file as specified on the command line (-Y option) as well as tweaking the board's IP address.
Utility to scan the device description for patterns (using standard regex). This makes it easier to locate registers without having to remember the full path name.
Several utility classes for interacting with CPSW ScalVals.
E.g., the SVL class automatically creates ScalVal interfaces
for all children of a hub (device). The user may then interact
(get/set) with individual registers by using their name:
mydev.set("registerX", 44)