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from pynq import MMIO
from pynq import PL
__author__ = "Giuseppe Natale"
__copyright__ = "Copyright 2016, Xilinx"
__email__ = "pynq_support@xilinx.com"
LEDS_OFFSET0 = 0x0
LEDS_OFFSET1 = 0x4
[docs]class LED(object):
"""This class controls the onboard LEDs.
Attributes
----------
index : int
The index of the onboard LED, starting from 0.
"""
_mmio = None
_leds_value = 0
def __init__(self, index):
"""Create a new LED object.
Parameters
----------
index : int
Index of the LED, from 0 to 3.
"""
if index not in range(4):
raise ValueError("Index for onboard LEDs should be 0 - 3.")
self.index = index
if LED._mmio is None:
base_addr = PL.ip_dict["leds_gpio"]["phys_addr"]
LED._mmio = MMIO(base_addr, 16)
LED._mmio.write(LEDS_OFFSET1, 0x0)
[docs] def toggle(self):
"""Flip the state of a single LED.
If the LED is on, it will be turned off. If the LED is off, it will be
turned on.
Returns
-------
None
"""
new_val = LED._leds_value ^ (0x1 << self.index)
self._set_leds_value(new_val)
[docs] def on(self):
"""Turn on a single LED.
Returns
-------
None
"""
new_val = LED._leds_value | (0x1 << self.index)
self._set_leds_value(new_val)
[docs] def off(self):
"""Turn off a single LED.
Returns
-------
None
"""
new_val = LED._leds_value & (0xff ^ (0x1 << self.index))
self._set_leds_value(new_val)
[docs] def write(self, value):
"""Set the LED state according to the input value.
Parameters
----------
value : int
This parameter can be either 0 (off) or 1 (on).
Raises
------
ValueError
If the value parameter is not 0 or 1.
"""
if value not in (0, 1):
raise ValueError("Value should be 0 or 1.")
if value:
self.on()
else:
self.off()
[docs] def read(self):
"""Retrieve the LED state.
Returns
-------
int
Either 0 if the LED is off or 1 if the LED is on.
"""
return (LED._leds_value >> self.index) & 0x1
@staticmethod
def _set_leds_value(value):
"""Set the state of all LEDs.
Note
----
This function should not be used directly. User should rely
on `toggle()`, `on()`, `off()`, `write()`, and `read()` instead
Parameters
----------
value : int
The value of all the LEDs encoded in a single variable
"""
LED._leds_value = value
LED._mmio.write(LEDS_OFFSET0, value)