Source code for pynq.lib.led

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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)