Source code for hwtLib.examples.statements.forLoopCntrl

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from hwt.code import If
from hwt.hdl.types.bits import HBits
from hwt.hwIOs.std import HwIOSignal, HwIOVectSignal, HwIORdVldSync
from hwt.hwIOs.utils import addClkRstn
from hwt.hwModule import HwModule
from hwt.hwParam import HwParam
from hwt.math import log2ceil
from hwt.pyUtils.typingFuture import override




class StaticForLoopCntrl(HwModule):
    """
    .. hwt-autodoc::
    """

    @override
    def hwConfig(self):
        self.ITERATIONS = HwParam(15)

    @override
    def hwDeclr(self):
        addClkRstn(self)

        self.cntrl = HwIORdVldSync()

        self.COUNTER_WIDTH = log2ceil(self.ITERATIONS)
        self.index = HwIOVectSignal(self.COUNTER_WIDTH)._m()
        self.body = HwIORdVldSync()._m()
        self.bodyBreak = HwIOSignal()

    @override
    def hwImpl(self):
        ITERATIONS = int(self.ITERATIONS)
        """
        Iterates from ITERATIONS -1 to 0 body is enabled by bodyVld and if bodyRd
        then counter is decremented for next iteration
        break causes reset of counter
        """

        counter = self._reg("counter", HBits(self.COUNTER_WIDTH), ITERATIONS - 1)

        If(counter._eq(0),
            If(self.cntrl.vld,
               counter(ITERATIONS - 1)
            )
        ).Else(
            If(self.body.rd,
                If(self.bodyBreak,
                    counter(0)
                ).Else(
                    counter(counter - 1)
                )
            )
        )

        self.cntrl.rd(counter._eq(0))
        self.body.vld(counter != 0)
        self.index(counter[self.COUNTER_WIDTH:0])



if __name__ == "__main__":
    from hwt.synth import to_rtl_str
    
    m = StaticForLoopCntrl()
    print(to_rtl_str(m))