cas.py

"""
Module which allows control via buttons and switches and status reporting via
LEDs.
"""

from mibuild.generic_platform import ConstraintError

from migen.bank.description import AutoCSR
from migen.bank.eventmanager import *
from migen.fhdl.std import *
from migen.genlib.misc import WaitTimer

from misoclib.com import gpio

class ControlAndStatus(Module, AutoCSR):
    def __init__(self, platform, clk_freq):

        # Work out how many LEDs this board has
        user_leds = []
        while True:
            try:
                user_leds.append(platform.request("user_led", len(user_leds)))
            except ConstraintError:
                break

        if user_leds:
            leds = Signal(len(user_leds))
            self.submodules.leds = gpio.GPIOOut(leds)
            for i in range(0, len(user_leds)):
                self.comb += [
                    user_leds[i].eq(leds[i]),
                ]

        # Work out how many switches this board has
        user_sws = []
        while True:
            try:
                user_sws.append(platform.request("user_sw", len(user_sws)))
            except ConstraintError:
                break

        if user_sws:
            switches = Signal(len(user_sws))
            self.submodules.switches = gpio.GPIOIn(switches)
            for i in range(0, len(user_sws)):
                self.comb += [
                    switches[i].eq(~user_sws[i]),
                ]

        # Work out how many push buttons this board has
        user_btns = []
        while True:
            try:
                user_btns.append(platform.request("user_btn", len(user_btns)))
            except ConstraintError:
                break

        if user_btns:
            self.submodules.buttons_ev = EventManager()

            _10ms = int(clk_freq*(10e-3))

            for i in range(0, len(user_btns)):
                btn_ev = EventSourceProcess()
                btn_timer = WaitTimer(_10ms)

                setattr(self.buttons_ev, "btn_ev{}".format(i), btn_ev)

                self.comb += [
                    btn_timer.wait.eq(user_btns[i]),
                    btn_ev.trigger.eq(~btn_timer.done),
                ]

                self.submodules += [btn_timer]

            self.buttons_ev.finalize()