# Copyright (c) 2013 Potential Ventures Ltd
# Copyright (c) 2013 SolarFlare Communications Inc
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"""
Collection of generators for creating bit signals.
Typically we use a single bit to control backpressure or insert IDLE
cycles onto a bus.
These yield a tuple which is intended to be interpreted as a number of
cycles ``(ON,OFF)``
"""
from cocotb.decorators import public
from cocotb.generators import gaussian, sine_wave, repeat
def bit_toggler(gen_on, gen_off):
"""Combines two generators to provide cycles_on, cycles_off tuples
Args:
gen_on (generator): generator that yields number of cycles on
gen_off (generator): generator that yields number of cycles off
.. deprecated:: 1.4.1
"""
for n_on, n_off in zip(gen_on, gen_off):
yield int(abs(n_on)), int(abs(n_off))
[docs]@public
def intermittent_single_cycles(mean=10, sigma=None):
"""Generator to intermittently insert a single cycle pulse
Args:
mean (int, optional): Average number of cycles in between single cycle gaps
sigma (int, optional): Standard deviation of gaps. mean/4 if sigma is None
.. deprecated:: 1.4.1
"""
if sigma is None:
sigma = mean / 4.0
return bit_toggler(gaussian(mean, sigma), repeat(1))
[docs]@public
def random_50_percent(mean=10, sigma=None):
"""50% duty cycle with random width
Args:
mean (int, optional): Average number of cycles on/off
sigma (int, optional): Standard deviation of gaps. mean/4 if sigma is None
.. deprecated:: 1.4.1
"""
if sigma is None:
sigma = mean / 4.0
for duration in gaussian(mean, sigma):
yield int(abs(duration)), int(abs(duration))
[docs]@public
def wave(on_ampl=30, on_freq=200, off_ampl=10, off_freq=100):
"""
Drive a repeating sine_wave pattern
TODO:
Adjust args so we just specify a repeat duration and overall throughput
.. deprecated:: 1.4.1
"""
return bit_toggler(sine_wave(on_ampl, on_freq),
sine_wave(off_ampl, off_freq))