Re: [myhdl-list] AttributeError: '_ConvertFunctionVisitor' object has no attribute 'funcBuf'

[Jan D. <ja...@ja...>]

Neal Becker wrote:
> Translating to verilog produced the above error. 

Mm, it seems the convertor has difficulties when an ordinary
function calls another ordinary function. Should work, I know :-)

Before showing a workaround below, I notice that you're also
using function calls to calculate constants inside generator
code. An important trick with conversion (because it is so
limited) is too keep as much as possible outside of generator
code. If possible, calculate constants outside generators 
and pass them as parameters - this way the computation can be
arbitrarily complex, as the convertor only needs to convert code used
inside generators.

The following modified code seems to convert fine:

def sat_rnd (x, bits, outbits):
    y1 = x >> (bits-1)
    y2 = y1 + 1
    y3 = y2 >> 1
    if (y3 > (2**outbits-1)):
        return 2**outbits - 1
    elif (y3 < - (2**outbits)):
        return - (2**outbits)
    else:
        return y3
    


def Counter (count, clock, en, n, reset):
    @always (clock.posedge, reset.posedge)
    def cntLogic():
        if reset == 1:
            count.next = 0
        elif en:
            if count == n-1:
                count.next = 0
            else:
                count.next = count + 1

#        print "count:", count
    return cntLogic

def accum (x, result, count, clock, en, n, reset):
    def log2 (x):
        "positive only!"
        cnt = 0
        while (x != 0):
            x >>= 1
            cnt += 1
        return cnt-1

    m = log2(n)
    sumbits = m  + len (result)
    _sum = Signal (intbv(0)[sumbits:])
    p = len(result)


    
    @always (clock.posedge, reset.posedge)
    def accum_logic():
        if reset == 1:
            _sum.next = 0
            result.next = 0
        elif en:
            _sum.next = _sum + x
            if count == n-1:
                ##print 'count:', count, 'sum:', _sum
                result.next = sat_rnd (_sum, m, p)
                _sum.next = 0

    return accum_logic

def Decimator (clock, en, x, n, count, result, reset):
    cnt1 = Counter (count, clock, en, n, reset)
    acc1 = accum (x, result, count, clock, en, n, reset)
    return cnt1, acc1




-- 
Jan Decaluwe - Resources bvba - http://www.jandecaluwe.com
    Python as a hardware description language:
    http://www.myhdl.org