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import time
import struct
from . import Pmod
from . import PMOD_NUM_DIGITAL_PINS
__author__ = "Yun Rock Qu"
__copyright__ = "Copyright 2016, Xilinx"
__email__ = "pynq_support@xilinx.com"
PMOD_PWM_PROGRAM = "pmod_pwm.bin"
CONFIG_IOP_SWITCH = 0x1
GENERATE = 0x3
STOP = 0x5
[docs]class Pmod_PWM(object):
"""This class uses the PWM of the IOP.
Attributes
----------
microblaze : Pmod
Microblaze processor instance used by this module.
"""
def __init__(self, mb_info, index):
"""Return a new instance of an GROVE_PWM object.
Parameters
----------
mb_info : dict
A dictionary storing Microblaze information, such as the
IP name and the reset name.
index : int
The specific pin that runs PWM.
"""
if index not in range(PMOD_NUM_DIGITAL_PINS):
raise ValueError("Valid pin indexes are 0 - {}."
.format(PMOD_NUM_DIGITAL_PINS-1))
self.microblaze = Pmod(mb_info, PMOD_PWM_PROGRAM)
# Write PWM pin config
self.microblaze.write_mailbox(0, index)
# Write configuration and wait for ACK
self.microblaze.write_blocking_command(CONFIG_IOP_SWITCH)
[docs] def generate(self, period, duty_cycle):
"""Generate pwm signal with desired period and percent duty cycle.
Parameters
----------
period : int
The period of the tone (us), between 1 and 65536.
duty_cycle : int
The duty cycle in percentage.
Returns
-------
None
"""
if period not in range(1, 65536):
raise ValueError("Valid tone period is between 1 and 65536.")
if duty_cycle not in range(1, 99):
raise ValueError("Valid duty cycle is between 1 and 99.")
self.microblaze.write_mailbox(0, [period, duty_cycle])
self.microblaze.write_blocking_command(GENERATE)
[docs] def stop(self):
"""Stops PWM generation.
Returns
-------
None
"""
self.microblaze.write_blocking_command(STOP)